fire safety valve oil free sample

The Remote Acting Oil Fire Valve is designed to safeguard against the risk of fuel being fed into the fire. When fitted to an oil supply line, fire safety valves can help to prevent total destruction by fire, which is why British Standard BS5410 states that oil supply lines should be protected by these valves. When the capillary sensors are exposed to excessive heat the fire valve closes tightly, preventing the main storage tank from fuelling the fire. Once they close as a precaution, theseremote acting oil fire valves will not reopen unless it is manually reset.Cut off temperature of 66°C or 90°C (depending on model)

Guide to OSVs - Oil Line Safety Valves: this article describes check valves and fusible link oil safety valves used on oil piping at heating appliances as both a fire safety device and to assist in oil burner servicing.

We explain the purpose of OSVs, which way to turn the OSV or oil line safety valve to open or close it, and we describe common oil line valve installation or use mistakes.

How & Where do We Install a Fusible-Link Firomatic™ Type Oil Safety Valve? This article series explains the installation & use of OSBs, or Fusible Link Oil Safety Valves. We describe and explain the differences in function and use among fusible link fire safety valves (OSVs) like the Firomatic®, vacuum operated OSVs like the Webster OSV and Suntec PRVs, oil line check valves, Tiger Loop and other oil system air removing devices, and oil delay valves or quick-stop valves that are also referred to as oil safety valves.

We explain where each valve is installed and what it does. We include oil safety valve and check valve troubleshooting advice, and we describe defects in heating oil piping & control valves.

The OSV or oil safety valve controls flow of fuel oil to the oil burner of oil-fired heating boilers, furnaces, and water heaters. This inline oil valve is intended to close automatically and thus stop the flow of oil in the oil line in the event of a fire.

Some suppliers use other names for this valve including the "Firomatic" valve (R.W. Beckett) or the "Oil Safety Valve OSVA-38" (Capital City Tool, Inc.).

Fusible Fire Safety Valves are designed to reduce fire damage by shutting off the flow of oil from the oil tank in the event of a fire. These valves conform to UL/ULC 842 and are listed in the US and Canada. They are required by code in residential oil heating installations in conformance with NFPA 31. - R.W. Beckett [4a]

Because the valve includes a fusible link (a lead or other soft metal core), in event of a fire the fusible link melts and the internal spring pushes the valve stem down, closing the valve and stopping oil flow.

Sometimes additional stop valves or OSVs may be installed at other locations (such as at the outlet of an above ground oil storage tank), but the critical location is at the oil burner since that"s a more likely location at which a fire may occur.

Watch out: the Firematic™ fusible-link automatic oil line shutoff valve (photo at left) should only be present on the oil supply line. We explain below

that installing an OSV on the return line of a two pipe oil system can lead to disaster. Instead, where it is necessary to prevent leakage from the return oil line during oil burner servicing we can install a simple one-way check valve on the oil return line (if the oil burner"s fuel unit manufacturer permits.)

Our photo at below left shows an example of a Firematic™ safety valve right at the oil burner. Synonyms people use for this valve include OSV, fire safety valve, oil line valve, Fire-o-Matic valve, Fusible link valve, oil line shutoff valve, oil safety valve, and Fireomatic valve.

In particular, the OSV shown here is installed between the oil filter canister and the fuel unit intake port. That means that it would be impossible to service the oil filter without spilling heating oil unless the service technician finds another oil line shutoff valve somewhere between the oil tank and the inlet side of the oil filter.

With the shutoff valve between the filter canister and the oil burner (above right), changing the oil filter in the canister will require the service tech to go to the more distant oil tank to find and close a valve in that location (if one is even present).

The technician moved the Fire-o-matic OSV to its proper location at the inlet side of the oil filter, and he also installed a Firomatic oil line check valve between the oil filter and the oil burner.

This is an important fire-safety detail as in event of a fire a closed valve on the return line (if it closes before the OSV on the supply line) could cause blowing seals on the oil pump or a blown oil line fitting, spewing fuel oil over the building fire.

In sum, the proper place for the fusible link oil valve (Fire-o-Matic Safety Valve™ for example) is on the oil supply line just before the inlet to the oil filter canister (red arrow, below left), not between the canister and the oil burner as shown at below right (orange arrow).

Below is another two-line oil system showing the OSV on the inlet side of the fuel filter canister just ahead of the oil burner and the oil return line exiting from the bottom of the fuel unit.

Regarding "the best location of an oil filter", NFPA 31 (2011): 7.5.8, for indoor tanks up to 330 gallons, requires that a thermally activated shutoff valve be placed inline as close as practical to the outlet from a tank and that a proper filter or screen be installed downstream and WITHIN SIX INCHES of the required thermally actuated valve. If it"s required in the code, it doesn"t have to "the best" - it just has to comply with the code.

With respect, Firebear, it is a fundamental error to suggest that "complying with code" is all that we need to think about in building and mechanical systems. Building codes specify the minimum requirements for acceptable practice. Often there are powerful reasons to do a better job than the bare minimum that"s required.

Many oil heat technicians sensibly want to install a fusible-link oil supply line valve at the oil burner, not only because this makes servicing the oil burner easier but because it also recognizes that the most-likely location of a fire is at the oil burner rather than possibly at a more distant oil storage tank.

The photograph above shows the right location for this safety device: at the input end of the oil filter. This permits the service technician to conveniently turn off the oil supply inorder to change the oil filter cartridge.

The writers of NFPA 31 (2011) 7.5.8 as specified above were focused on safety including wanting to avoid oil spills from the tank, but they might also have recognizede that putting an oil filter at the oil tank protects the oil line (between tank and oil burner) from sludge-clogging.

(Jan 23, 2014) oilman said: Your info is wrong. The filter belongs on the tank so it also protects the oil line. If you must install at the burner, it must be piped at least 12" from the pump. Hence why they make 12" flexible oil lines.

Reply: We agree that there is an advantage to protecting the oil line. However some HVAC instructors (including mine) teach that if the filter is not installed by the burner it is too often forgotten at service time.

When the oil tank is a bit more remote - across the garage and buried by the homeowner"s stored surfboards and hiking boots and boxes of tax receipts, the service tech enjoys being able to find the oil burner. Having inspected several thousand heating systems, my [DF] experience is that most of the time the OSV and filter are installed where they are convenient for service - which is usually close to the burner, notwithstanding the very good reasons for locating a filter at the inlet end of the oil line.

Our OPINION [DF] is that if the technician installs an OSV at the oil burner (and ahead of a filter if one is installed there), s/he should install a second OSV on the same oil supply line at the outlet from the oil tank, particularly if the oil tank outlet piping exits at the tank bottom, and ahead of the oil filter (if that"s where it"s installed).

In our OSV photos below, the first photo (below left) shows the oil line safety valve in the OPEN position - oil will flow when the threaded portion of the valve shaft extends fully up through the rotatable knob pointed to by my pencil.[Click any image to see an enlarged version. Thanks to reader Bernie Daraz for pointing out the need for these two photos]

In our heating oil line valve photo at above right the valve has been manually CLOSED - no oil will flow. The threaded valve stem has disappeared down into the valve body and has shut off the valve and oil flow.

Watch out: if (for example in case of a fire) the fusible link inside of an OSV has melted permitting the spring to close the valve, then from outside the valve may look as if it is in the open position - the threaded stem will still be poking out - but the valve has snapped and closed internally. Most likely you"ll know this also because there will have been a fire or other horrible event that melted the OSV fusible link.

Watch out: A simple oil line shutoff valve may not be a fusible-link safety valve. The simple shutoff valve might be any plumbing valve that can manually stop oil flow in the line, but it is not a safety device.

Make sure you"ve installed a fusible-link safety valve at each location where it"s most needed - at each oil burner. Even when one of these valves is installed at the oil tank the proper place for this protection is on the fuel oil supply line

In the event of a fire, if the return oil line valve closes before the supply line oil valve your oil burner pump may burst the oil line or it may cause a fuel pump gasket or seal to fail, leading to uncontrolled oil flow and perhaps worse, spray heating oil everywhere, possibly feeding the building fire.

Thanks to Dave Ferris for this fire safety tip and thanks to reader Rick Johnston for adding clarification. (Note that not oil burners use both an oil supply and oil return line between the oil tank and oil burner.)

Suntec points out in their installation literature for fuel units (oil pumps for oil burners) that pressures over 10 psi on an oil inlet line (normally running at a vacuum) may damage the shaft seal on the pump - i.e., leak heating oil.

Watch Out: If the oil line fire safety valves are missing or are not at the right location, we recommend immediate installation of a Fire-o-matic™ type oil line safety

Recommended (red arrow, photo above left): an automatic oil line shutoff valve on the oil supply line right at each and every individualoil burner: (a type that will shut off oil supply to the heating equipment in the event of a fire, such as a Fire-o-Matic™ valve) is shown in our photo at left.

By every oil burner, we mean for example that if your heating system and also your hot water heater each has its own oil burner then each burner should have an oil safety valve. (As in our photo above left).

A common but poor practice is to install an oil valve just at the oil tank or perhaps installing a single oil safety valve at the oil burner for the heating boiler but omitting the oil safety valve for the oil fired water heater in the same building.

A second oil line shutoff valve on the oil supply line at the oil tank (photo above right) is ok as long as you have also provided the first oil safety valve at the oil burner(s).

Some service technicians install a second oil safety valve at the oil tank or at another remote location away from the oil burner, such as at the building wall where an outdoor oil tank line enters the building, or right at the oil tank (photo at above right - this oil tank valve is leaking).

This second valve is helpful if it becomes necessary to replace the oil line between oil tank and oil burner. Although our photo above shows a fusible link oil valve at the oil tank, the oil line shutoff valve at the oil tank or at a location remote from the oil burner or other more likely fire sources can be a normal plumbing stop valve.

However a common exception we see in the field is an OSV at the oil burner and a second OSV (or perhaps a simple shutoff valve, not thermally linked) at the oil tank end of the oil line.

Teflon tape at OSV threaded oil line or fuel unit connections: Webster"s instructions and some other manufacturers also specifically warn: Do Not Use Teflon Tape. Use of teflon tape voids all warranties. (Webster 2011)

The concern is that should a fire occur in the building, and should an OSV on the oil return line close before the OSV on the supply line, the fuel unit may over-pressurize the oil lines, causing a burst oil line that then sprays high-pressure oil into the fire, increasing its size and spread-rate.

Use an oil line check valve instead. Or if the heating equipment manufacturer recommends against using a check valve in the oil piping system (Suntec prohibits, Webster recommends) then leave it out.

Our photo (left, red arrow) illustrates this hazard: you will see fusible link safety valves on both the oil feeder line (blue arrow, left side of photo before the oil filter canister) and the oil return line (red arrow, right side of the photograph).

Unlike a fusible link OSV that shuts in response to high temperature to provide fire protection at the oil burner, a vacuum operated OSV opens only in response to a "sustained vacuum" created at its outlet end when the oil burner"s fuel unit pump is drawing oil from the supply.

Vacuum-operated safety valves offer protection against oil line leaks and against overpressure conditions on the supply side of the fuel unit. They are not a fire-safety valve.

Protection against over-pressure from the supply piping prevents leaks at the fuel pump inlet or seals that might occur when the fuel pump is not operating but the supply piping is under pressure from the oil source.

If two oil lines are used to supply an oil burner, (a supply and a return) install an oil safety valve or OSV or fusible link oil line shutoff valve only on the oil supply line at the oil pump on the oil burner.Do NOT install an automatic oil line shutoff on the return oil line between the oil burner and the oil tank.

If a protection against oil back-flow at the return line is a concern, and if the manufacturer recommends it, use a check valve instead. Check valves like this one permit oil to flow just in one direction. They do not close down in event of a fire. Installed on the oil return line a check valve permits oil to flow from the oil pump in one direction only: back to the oil tank.

Typically the oil line de aerator device such as the Tigerloop is installed at the same location as the oil filter - just before oil enters the fuel unit (oil pump), as shown in our photograph at left, provided courtesy of reader E.I..

The Firomatic® oil line valve can be installed in ANY position - (vertical, horizontal, upside down) at least that"s what we were taught and what we have seen - the valve is spring loaded.

In a fire the fusible link, a lead core, melts at 165°F and a spring in the valve assembly snaps the valve shut to assure that the heating system does not feed oil to a building fire. It has to work in any orientation.

This list provides some of the companies produce fusible-link inline oil safety valves (OSVs). The footnote links point to the companies" contact information in our REFERENCES section, but generally you would purchase an OSV from your local heating equipment supplier or plumbing supplier.

AFL Industries, AFL OIL STOP VALVE PRODUCT BULLETIN [PDF] AFL Industries, 1101 West 13th St., Riviera Beach FL 33404 USA, Tel: 561-844-5200 includes OSV installation instructions for the contractor.

Bursey, Charles, "The Oil Safety Valve (Service)", Charles Bursey, Sr., Fuel Oil News, February 2006 (Still trying to get the full article - October 2008 - DF) Charles W. Bursey Sr. can be reached at F.W. Webb Co. www.fwwebb.com/

Cleanburn Energy CLEANBURN MULTI-OIL FURNACE OPERATORS MANUAL [PDF] (2009) Clean Burn Energy Systems, CLEAN BURN, INC. 34 Zimmerman Road Leola, PA 17540 U.S.A. includes Oil Safety Valve Installation Instructions

R.W. Beckett (U.S. & Canada) Firomatic Fire Safety Valves Beckett Corporation produces /distributes a wide range of oil burners & oil burner accessories * equipment including the oil safety valve (OSV) referred to as Firomatic® fusible fire safety valves, oil line check valves, and fusible link thermal switches

Beckett"s Firomatic® OSVs are provided in both 3/8" and 1/2" sizes and in flare and threaded designs. OSVs are provided designed for installation at the oil burner and in a different model at the oil storage tank.

Fusible fire safety valves are designed to reduce fire damage by shutting off the flow of oil from the oil tank in the event of a fire. These valves conform to UL/ULC 842 and are listed in the U.S. and Canada. They are required by code in residential oil heating installations in conformance with NFPA 31.

All[Firomatic® fire safety] valves are embossed with the direction of oil flow and include unique part number identification ring on each valve. The seal stem uses a double seal washer/o-ring system with high grade Viton® equivalent materials suitable for No. 2 fuel oil, kerosene, and jp to 205 biodiesel blend.

Oil under pressure or vacuum is supplied to the inlet of the PRV valve. Vacuum is required at the outlet of the PRV valve to open it and to allow oil to flow. When a burner starts, the pump will supply the vacuum necessary to open the valve. Any leak in the system which prevents vacuum from being exerted on the outlet port of teh valvewill prevent oil from flowing.

ISP Automation, Firomatic Globe Type Oil Line Valves & Lever Type Fusible Link Control Valves: ISP Automation, Inc., 1035 Old Georges Road, North Brunswick, NJ 08902, Phone: 866-383-3481, FAX 866-383-3482, Email: support@ispautomation.com http://www.ispautomation.com/

Webster "Service Technician"s Handbook, Webster Fuel Pumps & Valves" [handbook]. Webster Fuel Pumps & Valves, Capitol City Tool, Inc., http://www.websterfuelpumps.com/ , Division of Capital City Tool, Inc., Op. Cit.

Webster, OSV SERIES OIL SAFETY VALVES DIMENSIONS & SPECIFICATIONS [PDF] Fuel oil safety valves, Webster Fuel Pumps & Valves, web search 10/12/2011 original source http://www.websterfuelpumps.com/pdffiles/osv1.pdf

Webster, "Dimensions & Specifications, OSV Series Oil Safety Valves, OSVA 38, OSVA 50", Webster Fuel Pumps & Valves, (1980), Op. Cit. retrieved 2/24/2014, original source: http://www.websterfuelpumps.com/pdffiles/osv1.pdf

The current fusible link valve product properly named Firomatic is so widely also called "Firematic" and "Fireomatic" that we include those terms to assist readers in finding this information. Who manufactures the Firomatic fusible link valve? R.W. Beckett. Who manufactures vacuum-operated OSVs? Webster & Suntec (the PRV). We explain the differences among these products in this article series.

RW BECKETT RECALL for FIROMATIC 1/2" FEMALE PIPE THREAD FUSIBVLE SAFETY VALVE [PDF] P/N 12130 - the stem may not travel far enough to shut off the flow of fuel if exposed to trip point temperature. Posted until 4/1/2017, retrieved 2019/10/09 original source: https://static.globalindustrial.com/site/pdf/RW_Beckett_Firomatic_Female_Pipe_Thread_Recall.pdf

Excerpt: Recently, we became aware of a design deficiency in our ½” ‘Firomatic’ Fusible Safety Valve part number 12130. This bulletin covers ONLY the ½” FPT version p/n 12130, previous p/n B200F.

Under certain conditions, if the valve is exposed to temperatures exceeding the handle’s temperature rating and the valve ‘fires’ or actuates, the stem may not travel far enough to properly seat the valve and shut off the flow of fuel. This could result in a dangerous situation if there is a ruptured fuel line downstream of the valve. There have been no reports of this situation arising, but the potential for this issue to occur does exist. This does not affect the valve’s operation when used as a manual shut off valve.

The current design of the 12130 – ½” FPT valve and handle assembly was in production prior to R W Beckett’s acquisition of the Firomatic® product line. We have been unable to determine exact dates for any changes made to the design by previous manufacturers. Therefore this bulletin covers all Firomatic® ½” FPT valves, whether using our part number 12130 or the obsolete part number B200F, used by Highfield Manufacturing. Suspect valves can be identified by the name ‘Firomatic’ cast into the body of the valve. See illustration below.

A re-design of the 12130 valve will be available pending agency approvals and manufacturing process lead times. We are anticipating the re-designed valve to be available by January 1, 2017.

RW BECKETT RECALL for FIROMATIC 1/2" FEMALE PIPE THREAD FUSIBVLE SAFETY VALVE [PDF] P/N 12130 - OLDER COPY - the stem may not travel far enough to shut off the flow of fuel if exposed to trip point temperature. Posted until 4/1/2017, retrieved 2019/10/09 original source: https://static.globalindustrial.com/site/pdf/RW_Beckett_Firomatic_Female_Pipe_Thread_Recall.pdf

It might matter tremendously which way your OSV or oil safety valve is installed and in any event we ought to follow the manufacturer"s instructions including the flow arrow.

Here"s just one example. Some OSVs such as sold by Webster include a pressure-isolating feature that protects the fuel unit (the oil pump) from additional pressures that might come from the oil feed such as from an overhead oil feed line or even an elevated oil tank. Typically codes specify that the input pressure from the oil delivery piping ahead of the burner"s fuel unit not exceed 3 psi.

Those Webster OSVs include an internal valve that is designed to OPEN in RESPONSE to the FUEL UNIT OPERATION. So if the valve is installed backwards that feature will not work and the fuel unit may not pump oil properly to the burner nozzle.

Fusible Fire Safety Valves are designed to reduce fire damage by shutting off the flow of oil from the oil tank in the event of a fire. These valves conform to UL/ULC 842 and are listed in the US and Canada. They are required by code in residential oil heating installations in conformance with NFPA 31.

All valves are embossed with the direction of oil flow and include unique part number identification ring or each valve. The seal stem uses a double seal washer/ o-ring system with high grade Viton® equivalent materials suitable for No. 2 fuel oil, Kerosene and up to 20% Biodiesel blend.

I have shut off at the tank that is pointed in the correct direction and a second shut off at the burner end that is pointed in the wrong direction. it works properly as a shut off but will it work propoerly incase of fire? if it doesn"t matter then whats the purpose of the arrow?

Watch out: That"s because in the event of a fire a lead core in the valve is intended to melt to allow the valve to close - to stop feeding oil to a possible building fire. So if the valve is jammed it"s unsafe.

My concern is the stem does not go back into the valve or come out of it any further than it currently is no matter which direction I turn the valve or how many turns I make. Since the valve does not STOP turning in either direction, I"m concerned the valve is faulty.

If the stem pokes up out of the valve handle you"ve screwed the valve "down" and it is "open" to pass oil. Remember that these valves are threaded opposite of most others.

The knob on my OSV does not tighten up no matter how many times I turn it in either direction. The threaded stem in the center is protruding out about 2mm so I"m not sure if the valve is fully opened or closed. Is there a fix for this or do I need to replace the OSV?

If you have a fusible link valve that doesn"t seem to turn off you might try tapping the exposed end of the valve stem. I have found a stuck, or slow to close OSV on a few rare occasions. A gentle tap, not hard enough to damage threads, loosens it after which I open and close the valve a few times to convince myself it now moves freely. A burr on the brass interior or more likely internal sludge or debris could be the culprit.

Because at the oil burner the OSV is likely to be used at least once a year during service, that"s a good opportunity to discover if the valve is not closing fully.

In my opinion painting a fusible link is potentially unsafe - paint may interfere with mechanical operation of the valve. Most likely the manufacturer will agree, though they may not have imagined that event.

there must be an exception to the rule. my firematic valves open counter-clockwise and close clockwise and are definitely firematic valves because of their construction. they are just like the photos above but turn in the opposite direction you describe

I have a Themopride oil furnace that loses prime over night when the thermostat is lowed. It has a tigerloop installed. Why is there oil in the tigerloop if it loses prime?

Also, how do you recommend trouble shooting this? There are several valve one at each end of the supply line and one before the tigerloop that I could close for a few hours and see if it solves the problem (that would atleast narrow it down to a few fittings)

On a manual 1" fireomatic valve where the bonnett section joins the valve body, is that a brass on brass fit or is there suppose to be an o-ring or gasket? Does the OEM (Fireomatic) permitt valve disassembly for installation purposes? Thanks.

Mike I"ve installed these valves but have not tried disassembling one. If your unit is from Beckett, who currently provides the Fireomatic oil safety valve as well as the "New England Safety Switch" that uses a similar mechanism, then you might give them a call to ask.

Is there a inspection protocol for these valves like Morrison has on there fusible link valves (some quarterly inspections some yearly) and are they fine to use on gasoline lines I see only oil mentioned.

Watch out: do not use an oil line safety valve in ANY application other than those listed by UL and by the manufacturer - in this case, on heating oil supply lines.

Continue reading at OIL LINE SAFETY VALVE TURN DIRECTION to OPEN or SHUT or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

OIL LINE SAFETY VALVES, OSVs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

[1]AUDELS OIL BURNER GUIDE, INSTALLING, SERVICING, REPAIRING, [PDF online copy of this book] Frank D. Graham, Theo. Audel & Co., New York 1946, 1947, 1955 (out of print, copies occasionally available from antique book dealers and on EBay). Use THIS LINK to read a free online copy of this helpful classic textbook.

[2] Beckett Model SR Oil Burner Instruction Manual, R.W. Beckett Corporation, PO Box 1289, Elyria OH 44036 and R.W. Beckett Canada, Ltd., 430 Laird St., Guelph, Ontario, Canada N1G 3x7

[17] Newmac Furnaces & Boilers, "Installation, Operating, and Service Manual, Oil Fired Boiler Model NBR-2001 NBR 2002", (2007) Newmac Manufacturing, Inc., Debert Air Industrial Park, Lancaster Crescent, PO Box 9, Debert, Nova Scotia, BOM 1GO Canada, Tel: 902-662-3840, retrieved 2/23/2014

Thanks to Rick Johnston for pointing out that the more likely cause of a fire safety valve in the return oil line is a burst seal on the fuel unit 4/6/2009

Thanks to reader Bernie Daraz for suggesting the need for clear photographs illustrating the OSV or oil line safety valve in the open and closed positions. Personal correspondence 2/15/2013.

Thanks to reader T.R. for suggesting clarity on where oil safety valves should or should not be installed and for discussing the proper hook-up location for the Tigerloop and similar oil line prime protection & air removal devices. April 2011.

Thanks to reader Anonymous by request 2/23/2014, for requesting clarification of the safety hazards involved in placing an OSV on the return line of a two-pipe oil system.

TECHNICAL REFERENCE GUIDE to manufacturer"s model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop Weldon & Associates

Looking to expand your knowledge of fusible link valves? Here is the right place, this post will approach you with everything you need to know about the fusible safety valves, what is fusible link valve, and what’s the purpose. how they work, where they work for. Before learning you can review part of our project pictures as the following.

Fusible link safety shutoff valves are designed to automatically shut off flammable gases or liquids, solvents, alcohol, toxic liquids, or any other potentially hazardous media when the ambient temperature reaches a set value. In the event of a fire, the fuse of the automatic thermal shut-off device will automatically separate when it reaches a preset value, and then drive the actuator of the valve to close the valve(FC/NO) or open the valve(FO/NC).

The fusible link valve has different temperature settings, which can be freely selected according to the actual situation of the project. Generally, the set temperature of the fuse ball valve should be greater than the ambient temperature by 30°C. It is an ideal choice in the import and export system of flammable storage tanks. In addition, the fuse valve can be reused by simply replacing the broken fuse online during use, thereby reducing the cost of use.

Fusible link valve also called fire fuse valve, high-Temperature fusible valve, emergency shut-off valve, safety shut-off valve, fusible link safety shutoff valves,fire safe ball valve with automatic thermal shut-off device, fire-safe ball valve with automatic thermal shut-off device, fire-safe butterfly valves with automatic thermal shut-off device, thermal electrical shutoff valves.

The methanol emergency shut-off valve is a mechanical automatic reset safety protection device that uses a fused alloy chip to lock the spring force. When the ambient temperature reaches 100°C, the alloy dissolves, and the spring force expands to push the spool to close quickly. Widely used in combustible gas/liquid storage tanks and mechanical equipment, applications such as gas stations, oil depots, storage tanks, natural gas, liquefied gas, coal gas, methanol, toluene, biogas, liquid ammonia, ammonia, and fire protection facilities.

Fire safety fusible link valve-the fire safety ball valve with automatic thermal shutdown device (Thermal Shut-Off Valves), also known as fire cut-off valve, fire fuse valve, high-temperature fuse valve, without a power supply or air source. It’s s a kind of fire safety fire protection, the device is designed to automatically close the valve in the event of a high temperature or fire. The product has high-quality ball valves with API 607 fire protection certification.

Step 3. Connect the outlet end of the valve to the tanker pipeline: use a wrench to clamp on the octagonal surface of the outlet end of the valve to keep it, otherwise, the shear ring will be broken. Use another wrench to tighten the tanker pipe to be connected.

Note: Do not wrap PTFE tape on the threads, but apply a small amount of gasoline-resistant thread sealant to the pipe head. In order to avoid screwing the valve body, do not over-tighten when tightening. The recommended torque is 180N.m. (The recommended torque for tightening the test thread is 52N.m)

The emergency shut-off valve fastening device must be able to withstand a torque greater than 900N.m applied to each valve, the shear ring must be on the same level as the surface of the connecting foundation, and the height difference between the upper and lower sides must not be greater than 13mm. The fusible link valve is a necessary part of the machine, the user needs to construct it according to the foundation drawing provided by the main engine factory of the submersible pump tanker and strictly controls the relevant dimensions.

The valve is damaged or closed due to fire or vibration. Check whether the valve body is in good condition. Even if it is slightly damaged, please replace it immediately. In any case, before the valve is put into service again, the entire top of the connection and the top sealing ring should be replaced, and the valve must be retested.

Thestorage tank fusible link valve is installed on the oil storage tank inlet and outlet pipelines. When the tanker collapses or catches fire accidents, it can automatically and quickly cut off the oil flow. When the storage tank’s ambient temperature reaches a certain value or the fire reaches a certain temperature, the fuse ring of the fusible link valve melts and the valve closes automatically. It does not require an electric/pneumatic actuator to drive the valve.

This kind of structure of the fire blocking valve has a simple structure, ingenious design, and reasonable layout. Its unique structure can automatically trigger a series of mechanism actions after the ambient temperature reaches a certain range, and rely on the mechanical energy (spring elastic potential energy) used as the power source to realize the closing operation of the valve, thereby realizing the purpose of automatically cutting off the medium delivery in a short time. Installing this kind of fire blocking valve on a storage tank containing a flammable and explosive flame-retardant barrier can automatically react in a short time and reduce the output of combustible media as much as possible, thereby contributing to fire control in the event of an accident. Therefore, it can be said that it has many advantages and is particularly suitable for popularization and application in this field, and its market prospect is very broad.

The oil tank fusible link valve is installed on the inlet and outlet pipelines of the flammable storage tank. When the ambient temperature reaches the set value or the fire reaches the set temperature, the fusible link valve can automatically and quickly cut off the valve that closes the pipeline medium. The fusible link valve does not require power or air supply, and it can be automatic close. fusible link ball valves for diesel fuel tank

Oil tank fusible valves are usually installed on the outlet and inlet of oil tanks or flammable liquid storage tanks. When the ambient temperature of the fusible link valve reaches the set temperature of the fuse link, the flux on the fuse link begins to melt and break, then the fusible link valve starts to drive the valve action under the action of the preload of the return spring, and to make the valve open or close, so as to open or cut off the medium in the valve and achieve fire prevention purposes. There is a fusible ring in the fusible link valve, when the ambient temperature reaches a certain value or the fire reaches a certain temperature, the valve fuse ring will fuse and the valve will automatically close. It does not require an electric/pneumatic actuator to drive the valve.

Mechanical principle design, no need for manual operation or external force to close the system, the fire itself can trigger the automatic shutdown of the device, safe and reliable.

The fusible link valve of a diesel generator set includes a valve body and an actuator. The valve body and the actuator are fixed by a fixed bracket. The actuator includes a shaft, a fuse actuator, a manual(handwheel), an actuator protection cover, and a signal feedback device. The fuse valve can be reused as long as the broken fuse is replaced during use, thereby reducing the use cost.

Many diesel generator sets still generally use manual shut-off valves, and electric or pneumatic shut-off valves. However, the control methods of these valves prevent the operators from being able to close the valves quickly in emergencies during fires, explosions, and other accidents. Or the shut-off valve cannot be approached due to the harsh conditions at the accident site, so the function of the electric or pneumatic shut-off valve system is damaged. Or when the coil of the shut-off valve is accidentally charged, the automatic shut-off valve will open automatically, making it can’t to cut off the pipeline. Therefore, the leakage of flammable gas or liquid, solvent, methanol, toxic liquid, or any other potentially dangerous medium may cause a certain amount of personal injury to the person who performs the closing action or cause the failure to close the pipeline in time to further expand the accident.

When the customer received the fusible link valves, you can re-installation these valves refer to the below guide. Remove the 4 screws on top of the actuator.

If you are interested in more information about the fusible link fuel shut-off valve, fusible link valve Singapore, fusible link valve symbol, fusible link ball valve, fusible link ball valve, fusible link valve operation, and 2” fusible link oil safety valves, welcome to send your requirements to our email, marketing@cncontrolvalve.com or WhatsApp +86 185 1656 9221

Fusible link valves aren’t complicated as control valves, but it is so important due to their application, we make sure every valve has a fire-safe function, and the fusible link should be verified. THINKTANK supplies fusible link safety valves for many distributors, and they have no worries about the valve quality, delivery time, affordable costs, and reliable performance. Just feel free to contact us if you are working in this niche market, and we believe we can create more value together.

The primary purpose of a safety valve is to protect life, property and the environment. Safety valves are designed to open and release excess pressure from vessels or equipment and then close again.

The function of safety valves differs depending on the load or main type of the valve. The main types of safety valves are spring-loaded, weight-loaded and controlled safety valves.

Regardless of the type or load, safety valves are set to a specific set pressure at which the medium is discharged in a controlled manner, thus preventing overpressure of the equipment. In dependence of several parameters such as the contained medium, the set pressure is individual for each safety application.

R.W. Beckett’s burner controls were created with customer satisfaction and safety in mind. Our entire suite of burner controls utilizes the most current technology to safely control the combustion process.

We advance safety by finding smarter ways to help safeguard businesses and protect people where they live and work. Using proven and trusted technology, we offer a versatile line of fire valves for diverse applications, including oil and gas, energy and power generation, tunnels and transportation, storage facilities, commercial, industrial, or residential systems.

A fire-safety shut-off valve, also known by thermal shut-off valve or simply afusible link valve, is a safety device designed to provide automatic valve shut-off in the event of a fire. Fire-safety valves of this type are designed for facilities that utilize flammable or toxic gases and chemicals in their production or for fuel systems of all types.

The fusible link is an FM and/or UL approved two-part linkage held together by a specialized heat-sensitive solder. These link(s) hold the fire safety valve open by keeping tension on a spring pack through a trigger assembly.

A fire safety shut-off valve is comprised of five main components – API 607 fire-safe valve, spring pack, mounting hardware, trigger assembly, and fusible link. The last four of these components work in unison to close the API 607 valve should a fire be detected within a facility.

The fusible link portion is the linchpin of the assembly and keeps the fire safety valve open by keeping tension on a spring pack through the trigger assembly. When a fire breaks out, the link separates when its rated temperature is met, releasing the spring pack and allowing it to close the valve.

The API 607 standard is a specification for the fire testing of quarter-turn valves. For fire-safety valve with fusible links, this means that the valves have a primary drop-tight seat, typically made of TFE, along with a secondary seat made of metal for isolation in a fire. The secondary seat is coupled with graphite seals for further protection. This means the top works of the shut-off valve can be paired with any quarter-turn API 607 fire safe valve – ball valve, butterfly valve, or plug valve.

Fusible link fire-safety valves are used in a variety of industries within an organization’s overall fire safety system for widespread fire protection. Most modern facilities have at diesel generators and day tanks that that requires this type of safety valve at a minimum. Other locations where flammable or toxic media are part of the production process, this valve type is placed at strategic locations throughout facilities including storage tanks, pumps, entryways into a building, and at key piping junctions. Entryways into buildings are especially key so that have employees, customers, and patients have as much time for notification and evacuation as possible.

A fire safety valve should be used as a safety precaution on any system that utilizes flammable or hazardous media. Designed to save lives and enable quick resumption of operations after a fire has been handled, fusible link assemblies are necessary for the safe daily operations of many commercial operations, plants, and manufacturing facilities. Many of these operations will find that insurance for their business is not available without a fire safety valve with fusible link.

BI-TORQ has been designing this type of assembly for over two decades. Let’s have a conversation about your fire safety needs and how our products can provide safety for your workers and operation. Contact us for more information on fire safety valves with fusible links, or to discuss any of our wide range of valve solutions.

Our Fire-Safe Thermal Shut-off Assemblies are engineered for automatic shut-off in case of a fire. They are ideal for flow shut-off protection in systems conveying flammable gasses or liquids such as fuel, solvents, alcohols, toxic chemicals, or other potentially dangerous media.

Two Classifications:Thermal Shut-Off Fusible Link Packages (FLP Ball ValvesandFLP Butterfly Valves): “sentry-type” protection for local isolation. FM approved actuators on assemblies through 3,960 in/lbs of torque and designed for fire-safe certified quarter-turn ball, butterfly, or plug valves with torques up to 21,000 in/lbs depending on media, pressure, and other conditions. This series is ideal for customers or end-users who must use plant-specified valves. We have also designed adapter kits for leading valve manufacturers to create a high-quality package for API 607 fire-safe certified valves. Customers send specified valves to our facility, where we assemble and test by our experienced team so that they are ready to install in line when they arrive on your dock. And upon request, we can also offer start-up and commissioning.

Thermal-Electric (TES Series): provides local thermal protection. This series allows a single operator to transmit a low-voltage signal to a thermal-electric fusible link via a command device or PLC. The voltage causes the link to yield, releasing the spring and closing the valve. The TES design can control a single assembly or an entire bank and doubles as a thermal shut-off, which will trigger when the surrounding temperature exceeds the link’s rating. The TES system has revolutionized fire safety systems by allowing isolated and group valve shut-offs from one operating location in the event of an emergency, without the need for compressors, pneumatic lines, and other expensive and time-consuming apparatus. This series is not FM Approved.

BI-TORQ Valve Automation, dedicated to providing only the highest quality, dependable shut-off valves for critical applications. From automatic shut-off valves for oil and gas refineries to thermal shut-off valves for your facility’s fire protection systems, we have the equipment, expertise, and experience necessary to ensure that your system operates with the utmost safety and efficiency.

In order to ensure that the maximum allowable accumulation pressure of any system or apparatus protected by a safety valve is never exceeded, careful consideration of the safety valve’s position in the system has to be made. As there is such a wide range of applications, there is no absolute rule as to where the valve should be positioned and therefore, every application needs to be treated separately.

A common steam application for a safety valve is to protect process equipment supplied from a pressure reducing station. Two possible arrangements are shown in Figure 9.3.3.

The safety valve can be fitted within the pressure reducing station itself, that is, before the downstream stop valve, as in Figure 9.3.3 (a), or further downstream, nearer the apparatus as in Figure 9.3.3 (b). Fitting the safety valve before the downstream stop valve has the following advantages:

• The safety valve can be tested in-line by shutting down the downstream stop valve without the chance of downstream apparatus being over pressurised, should the safety valve fail under test.

• When setting the PRV under no-load conditions, the operation of the safety valve can be observed, as this condition is most likely to cause ‘simmer’. If this should occur, the PRV pressure can be adjusted to below the safety valve reseat pressure.

Indeed, a separate safety valve may have to be fitted on the inlet to each downstream piece of apparatus, when the PRV supplies several such pieces of apparatus.

• If supplying one piece of apparatus, which has a MAWP pressure less than the PRV supply pressure, the apparatus must be fitted with a safety valve, preferably close-coupled to its steam inlet connection.

• If a PRV is supplying more than one apparatus and the MAWP of any item is less than the PRV supply pressure, either the PRV station must be fitted with a safety valve set at the lowest possible MAWP of the connected apparatus, or each item of affected apparatus must be fitted with a safety valve.

• The safety valve must be located so that the pressure cannot accumulate in the apparatus viaanother route, for example, from a separate steam line or a bypass line.

It could be argued that every installation deserves special consideration when it comes to safety, but the following applications and situations are a little unusual and worth considering:

• Fire - Any pressure vessel should be protected from overpressure in the event of fire. Although a safety valve mounted for operational protection may also offer protection under fire conditions,such cases require special consideration, which is beyond the scope of this text.

• Exothermic applications - These must be fitted with a safety valve close-coupled to the apparatus steam inlet or the body direct. No alternative applies.

• Safety valves used as warning devices - Sometimes, safety valves are fitted to systems as warning devices. They are not required to relieve fault loads but to warn of pressures increasing above normal working pressures for operational reasons only. In these instances, safety valves are set at the warning pressure and only need to be of minimum size. If there is any danger of systems fitted with such a safety valve exceeding their maximum allowable working pressure, they must be protected by additional safety valves in the usual way.

In order to illustrate the importance of the positioning of a safety valve, consider an automatic pump trap (see Block 14) used to remove condensate from a heating vessel. The automatic pump trap (APT), incorporates a mechanical type pump, which uses the motive force of steam to pump the condensate through the return system. The position of the safety valve will depend on the MAWP of the APT and its required motive inlet pressure.

This arrangement is suitable if the pump-trap motive pressure is less than 1.6 bar g (safety valve set pressure of 2 bar g less 0.3 bar blowdown and a 0.1 bar shut-off margin). Since the MAWP of both the APT and the vessel are greater than the safety valve set pressure, a single safety valve would provide suitable protection for the system.

Here, two separate PRV stations are used each with its own safety valve. If the APT internals failed and steam at 4 bar g passed through the APT and into the vessel, safety valve ‘A’ would relieve this pressure and protect the vessel. Safety valve ‘B’ would not lift as the pressure in the APT is still acceptable and below its set pressure.

It should be noted that safety valve ‘A’ is positioned on the downstream side of the temperature control valve; this is done for both safety and operational reasons:

Operation - There is less chance of safety valve ‘A’ simmering during operation in this position,as the pressure is typically lower after the control valve than before it.

Also, note that if the MAWP of the pump-trap were greater than the pressure upstream of PRV ‘A’, it would be permissible to omit safety valve ‘B’ from the system, but safety valve ‘A’ must be sized to take into account the total fault flow through PRV ‘B’ as well as through PRV ‘A’.

A pharmaceutical factory has twelve jacketed pans on the same production floor, all rated with the same MAWP. Where would the safety valve be positioned?

One solution would be to install a safety valve on the inlet to each pan (Figure 9.3.6). In this instance, each safety valve would have to be sized to pass the entire load, in case the PRV failed open whilst the other eleven pans were shut down.

If additional apparatus with a lower MAWP than the pans (for example, a shell and tube heat exchanger) were to be included in the system, it would be necessary to fit an additional safety valve. This safety valve would be set to an appropriate lower set pressure and sized to pass the fault flow through the temperature control valve (see Figure 9.3.8).

Oil and gas operations ranging from refining to distribution, are significantly reliant on pipeline systems. Infrastructure and trustworthy control systems are therefore crucial in the business. In this scenario, oil and gas valves are essential to ensure the safety of the industrial operations of pipelines.

This post will focus on explaining different types of industrial valves, their mechanism, their application in the oil and gas industry as well as API and ASME standards for oil and gas valves.

Valves regulate and steer the flow of fluids (such as gaseous and liquidized materials) by opening and closing routes or partially blocking passageways. Technically, valves are fittings, but they’re commonly treated as individual components. Whenever a valve is open, fluid flows from higher to lower pressure.

Valves used in the industry come in a variety of shapes and sizes. Different types of valves are gate valves, globe valves, ball, butterfly, and check valves as well as pressure and diaphragm valves These valves perform a variety of purposes.

Due to their widespread use in commercial construction projects and automation projects, it is expected that the demand for industrial gas valves will increase in the upcoming years. Due to technological advancements, increased industrialization and expansion of existing facilities have sparked demand and boosted the industry’s growth.

Different types of industrial valves mentioned above are used for various purposes. Some major processes that have valve applications include water and sewage treatment, mining and power generation, as well as the refining of petroleum products.

It is possible to operate a valve manually, whether it functions with a handle or lever. Alternatively, valves can be set up to operate automatically in response to a change in pressure These changes may act on a diaphragm or a piston, which in turn activates the valve.

There are more complex control systems that require an actuator, such as for regulating the flow of water through pipes depending on external input. As a result of its input and set-up, the valve may be precisely positioned and controlled to meet a variety of requirements.

There are several valves that differ in design and operation. A difference in design leads to a big change in their industrial applications. Different types of industrial valves are discussed below:

The flow of media is controlled by a gate valve that lifts and lowers the gate. The straight-through, unobstructed path of a gate valve is its distinguishing feature, resulting in minimal pressure loss across the valve.

Unlike butterfly valves, the unobstructed bore of a gate valve allows a pig to pass through during pipe cleaning procedures. Gate valves come in a variety of sizes, materials, temperature, and pressure ratings, as well as gate and bonnet styles.

In a pipeline, a globe valve controls the flow. It’s a device that allows you to control or stop the flow of liquid or gas through a pipe. This type of valve gets its name from the fact that it has an internal baffle that divides it into two halves. They are also known as throttle valves.

Although these valves have slightly higher pressure drops than other valves, they can be employed in various situations where the valve’s pressure drop is not a constraint.

An industrial ball valve is a shut-off valve that uses a rotatable ball with a bore to control the flow of a liquid or gas. You can limit or allow the medium to flow by rotating the ball 90 degrees around its axis for a quarter revolution. While not in use for an extended period of time, they nonetheless provide a firm seal. In addition, they are more resistant to polluted media than most other valve types.

Ball valves can also be utilized as a control valve in specific variants. Because the flow rate control precision is less precise than with other types of control valves, this application is less popular.

A check valve is a unidirectional valve. It only allows one direction of fluid flow. They have two ports, one for the media inlet and one for the media output. They are known as one-way valves or non-return valves because they only allow media to flow in one direction. A check valve’s primary function is to prevent backflow in the system.

A pressure differential is required for an industrial check valve to function. To open the valve, they require more pressure on the input side than on the output side. The valve closes when the pressure on the output side is higher (or when the pressure on the input side is insufficient). The closure mechanism differs depending on the valve type. They do not require a handle, lever, actuator, or human to function properly, unlike other valves.

A pinch valve is a two-way valve that is used to control or shut off the flow of corrosive, abrasive, or granular material. Compressed air is used to open or seal the valve.

Open, the valve allows a wide variety of media to pass through its bore. Valves are designed to isolate the medium from contamination by using flexible rubber sleeves inside of them. Slurries and granular goods such as sand, cement, gravel, textile fiber, charcoal, powder, pellets, chipping, glass pieces, and so on are highly compatible with pinch valves.

These valves are affordable, and simple to operate, making them ideal for a variety of industrial applications. Get them from reliable gas valve suppliers for innovative solutions tailor-made to suit your requirements.

Butterfly valves are part of the quarter-turn valve family and function similarly to ball valves. A disc is linked to a rod to form the “butterfly.” When the rod turns the disc a quarter turn perpendicular to the flow direction, it closes. The disc is rolled back to enable flow when the valve opens.

Industrial butterfly valves are popular because of their lightweight, compact installation footprint, lower prices, rapid operation, and availability in extremely large sizes. Handles, gears, and automatic actuators can all be used to operate these valves.

To safeguard the system from overpressure, a safety valve is used. When the pressure surpasses the Maximum Allowable Working Pressure or the pressure for which the system was built, overpressure develops. When opposed to relief valves, safety valves can open quite quickly. A safety valve opens from a predetermined pressure; the valve opens slowly at first, then fully to remove the undesirable pressure from the system as rapidly as feasible.

Safety valves are used to keep pressure from rising too high, causing malfunctions, fires, or explosions. Because safety valves have no electrical or pneumatic components, they are employed when electronic or pneumatic safety mechanisms fail. Approach fully-functional production Oil valves suppliers for the best output.

A plug valve is a cone-shaped valve that rotates inside the valve body to control the flow of the fluid. One or more hollow channels are commonly positioned horizontally in plug valves to allow easy flow through the valve while it is open.

The two-port plug valve, which has an open and closed state, is the most popular. In such a valve, one route flows from inbound to outbound, while the stem and handle are located on the top of the valve. A quarter-turn valve is also used in an industrial plug valve, which is advantageous when a quick and frequent operation is required.

Industrial valves manufacturers use various materials in making different types of valves. The material is selected according to the valve’s function and application. Here are some of the common materials that industrial valves are made up of:

As a non-reactive metal, stainless steel is used in making many industrial valves. Each gauge requires a precise mix of metals such as chromium, nickel, or molybdenum. Stainless steel valves are suited for handling corrosive media such as saline marine water, acids, and halide gases as they do not corrode the body of the valve. In some cases, brass can be a good replacement for steel.

Cast steel valves are created by pouring molten steel into a mold and allowing it to solidify under controlled conditions. On the one hand, if done correctly, this procedure produces solid valves and is a practical low-cost method of production.

However, because it is prone to holes and tears where the molten steel has not formed evenly, it requires continuous monitoring and quality control. Furthermore, if the molten steel was of poor quality, the valve will be faulty as well.

Forged steel valves are made by shaping metal using extreme heat and mechanical equipment. Instead of being poured into a ready-made mold, steel is bent and shaped into the shape of the valve using tools. The benefit of this is that heat tends to harden the metal, resulting in stronger and longer-lastingindustrial valves. On the other hand, because it is constructed as a whole, the connections between various elements may be a source of leaks. Forged steel valves are likewise more expensive due to the additional labor involved.

The body of the valve is the outer casing that houses the internal pieces or trim of most or all of the valve. In commonly used valve designs, the body is usually screwed to the bonnet.

Valve bodies are often made of metal or plastic. Due to its corrosion resistance qualities, particularly against warm saltwater, duplex and super duplex valves are frequently used in seawater applications such as desalination facilities. Bonnet

On the valve body, a bonnet serves as a cover. It’s usually screwed or bolted into the valve body semi-permanently. A bonnet keeps everything together inside the valve. Users can remove the bonnet of a valve to gain access to internal parts, usually for maintenance. Many industrial valves lack bonnets; for example, plug valves are frequently devoid of bonnets. Many ball valves do not have bonnets because the valve body is assembled differently, for example by screwing the valve body together in the center. Ports

The channels that allow fluid to travel through the valve are known as ports. To control flow, the valve part or disc obstructs ports. Valves typically have two ports, but they can have as many as twenty. Almost always, the valve’s ports are connected to pipes or other components. Threadings, compression fittings, adhesive, cement, flanges, and welding are all examples of connection methods. Actuator

From outside the valve body, a handle is utilized to physically regulate the valve. Automatic valves do not have handles. However, some, such as stop-check valves, have a handle for manual overriding purposes. An actuator automatically or remotely operates a valve from outside the body. Some valves, such as check valves and relief valves, have neither a handle nor an actuator since they operate automatically from the inside. Disc

A disc, also known as a valve member, is a moveable barrier within the stationary body that restricts flow via the valve in various ways. Discs come in a variety of shapes, despite their classic disc shape. A disc can travel linearly inside a valve, rotate on the stem, or revolve on a hinge or trunnion, depending on the type of valve. A ball is a round valve part that passes through one or more routes between ports. Flow can be steered between different ports by spinning the ball. Spherical rotors with a cylindrical hole drilled as a fluid route are used in ball valves.

Plug valves use plugs, which are cylindrical or conically tapered rotors. Rotor valves can also have any round rotor shapes as long as the rotor can be spun inside the valve body. However, a ball check valve employs the ball to stop the backward flow but is not a rotor because the ball does not rotate while the valve is operated. Seat

The seat is the body’s interior surface that makes contact with the disc to create a leak-tight seal. Only when the valve is closed does the disc come into touch with the seat if it moves linearly or swings on a hinge or trunnion. The seat is always in touch with the disc in rotating discs, although the area of contact changes as the disc rotates. In relation to the body, the seat is constantly immobile. Stem

The stem can transfer a linear force, a rotational torque, or a combination of these motions. The stem can be screwed into or out of the valve by rotating it in one way or the other. This allows th