lpg safety valve free sample

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.

LPG bulk storage products need to be built right using quality materials, to provide years of reliable, safe service. That’s why you need to ask for RegO. We design, built and test 100% of our products in America to ensure you get years of service from all the valves, safety systems and accessories your system requires. When you buy RegO quality, you reduce service time and routine maintenance is easier, that saves you time and money.

RegO LPG bulk storage products are backed by our worldwide network of knowledgeable technical and sales support. And we provide an industry-leading 10-year warranty for all our LPG bulk storage products.

RegO internal valves are easily installed and designed to enable smooth operation and higher pumping rates without cavitation or loss of efficiency to save you time and money. They require maintenance less often than other internal valves, and the maintenance is fast and easy. We pay attention to the details, such as superior corrosion prevention and securing fasteners so they don’t come loose and cause damage.

RegO relief valves provide superior protection matched with a long service life. Specifically designed for large stationary pressurized containers our manifold designs provide for an extra relief valve, not included in the flow rating, to enable service or replacement without evacuating the container.

RegO MultiPort relief valve manifolds are used as the primary relief device on LPG bulk storage tanks with flanged openings. The handwheel selectively closes the entrance port to enable service or repair without tank evacuation. RegO “pop-action” design ensures maximum protection, with minimum product loss when replacing a relief valve.

RegO DeltaPort relief valve manifolds are designed to be the primary relief device on LPG bulk storage tanks. The handwheel selectively closes the entrance port to enable service or repair without tank evacuation.

These low profile, internal relief valves are constructed of non-corrosive materials and the RegO “pop-action” design ensures maximum protection, with minimum product loss on relief.

RegO A7500 Series globe valves are constructed with high-quality materials and come in a range of sizes for use in LPG bulk storage applications. Purposefully designed to ensure greater flow with less pressure drop, positive shut-off, and long maintenance-free service; our globe valves provide safety and peace of mind for years. RegO globe valves include these standard features:

At RegO, system and operational safety are paramount. We provide a complete line of products built with RegO ingenuity and quality to deliver years of safe operation.

RegO Back Pressure Check Valves are designed to allow flow in one direction only. When the flow stops or reverses, the check closes. Built to provide generous flow channels for low pressure drop, the heavy-duty construction and synthetic rubber seat discs deliver positive seals for years.

Available in 2” and 3” connections, this back check valve provides back flow protection for the unloading riser. Easy-to-read indicator, heavy-duty spring-loaded swing check design, delivers high flow rates with low pressure drop.

Designed for LPG transfer lines to provide quick shut off of liquid or vapor in the event of an accidental pull-away, line break, or hose rupture. Fusible thermal element auto-shuts valve when exposed to fire. Available with flanged or threaded connections, Viton and Buna-N seat seal options, and a choice of manual, pneumatic, rotary, or electric activation.

Vents less than 2 cc of liquid when disconnected (when connected to RegO low emission ACME filler valves 6588LE, 6589LE.). This valve provides a full-on flow when pressing the release trigger. Compatible with any standard 31⁄4” male ACME connector. California CARB Compliant.

Designed to promote maximum pump and compressor efficiency, these indicators enable visual inspection of liquid flow. The integral swing check also serves as a back-check valve to prevent reverse flow and product loss if the hose fails in a loading operation. Durable ductile iron body ensures long, trouble-free operation with design working pressure of 400 PSIG.

Designed to provide an accurate determination of LPG container contents, they mount in a standard 1” NPT coupling. Resistance-free nylon bearing inserts reduce friction and promote operating ease, and the dial face is dual calibrated to provide greater accuracy in reading contents in containers which are not level.

Designed especially for the protection of piping and shut-off valves where there is a possibility of trapping liquid LP-Gas or anhydrous ammonia. Available in both brass and stainless steel.

A safety valve must always be sized and able to vent any source of steam so that the pressure within the protected apparatus cannot exceed the maximum allowable accumulated pressure (MAAP). This not only means that the valve has to be positioned correctly, but that it is also correctly set. The safety valve must then also be sized correctly, enabling it to pass the required amount of steam at the required pressure under all possible fault conditions.

Once the type of safety valve has been established, along with its set pressure and its position in the system, it is necessary to calculate the required discharge capacity of the valve. Once this is known, the required orifice area and nominal size can be determined using the manufacturer’s specifications.

In order to establish the maximum capacity required, the potential flow through all the relevant branches, upstream of the valve, need to be considered.

In applications where there is more than one possible flow path, the sizing of the safety valve becomes more complicated, as there may be a number of alternative methods of determining its size. Where more than one potential flow path exists, the following alternatives should be considered:

This choice is determined by the risk of two or more devices failing simultaneously. If there is the slightest chance that this may occur, the valve must be sized to allow the combined flows of the failed devices to be discharged. However, where the risk is negligible, cost advantages may dictate that the valve should only be sized on the highest fault flow. The choice of method ultimately lies with the company responsible for insuring the plant.

For example, consider the pressure vessel and automatic pump-trap (APT) system as shown in Figure 9.4.1. The unlikely situation is that both the APT and pressure reducing valve (PRV ‘A’) could fail simultaneously. The discharge capacity of safety valve ‘A’ would either be the fault load of the largest PRV, or alternatively, the combined fault load of both the APT and PRV ‘A’.

This document recommends that where multiple flow paths exist, any relevant safety valve should, at all times, be sized on the possibility that relevant upstream pressure control valves may fail simultaneously.

The supply pressure of this system (Figure 9.4.2) is limited by an upstream safety valve with a set pressure of 11.6 bar g. The fault flow through the PRV can be determined using the steam mass flow equation (Equation 3.21.2):

Once the fault load has been determined, it is usually sufficient to size the safety valve using the manufacturer’s capacity charts. A typical example of a capacity chart is shown in Figure 9.4.3. By knowing the required set pressure and discharge capacity, it is possible to select a suitable nominal size. In this example, the set pressure is 4 bar g and the fault flow is 953 kg/h. A DN32/50 safety valve is required with a capacity of 1 284 kg/h.

Coefficients of discharge are specific to any particular safety valve range and will be approved by the manufacturer. If the valve is independently approved, it is given a ‘certified coefficient of discharge’.

This figure is often derated by further multiplying it by a safety factor 0.9, to give a derated coefficient of discharge. Derated coefficient of discharge is termed Kdr= Kd x 0.9

Critical and sub-critical flow - the flow of gas or vapour through an orifice, such as the flow area of a safety valve, increases as the downstream pressure is decreased. This holds true until the critical pressure is reached, and critical flow is achieved. At this point, any further decrease in the downstream pressure will not result in any further increase in flow.

A relationship (called the critical pressure ratio) exists between the critical pressure and the actual relieving pressure, and, for gases flowing through safety valves, is shown by Equation 9.4.2.

Overpressure - Before sizing, the design overpressure of the valve must be established. It is not permitted to calculate the capacity of the valve at a lower overpressure than that at which the coefficient of discharge was established. It is however, permitted to use a higher overpressure (see Table 9.2.1, Module 9.2, for typical overpressure values). For DIN type full lift (Vollhub) valves, the design lift must be achieved at 5% overpressure, but for sizing purposes, an overpressure value of 10% may be used.

For liquid applications, the overpressure is 10% according to AD-Merkblatt A2, DIN 3320, TRD 421 and ASME, but for non-certified ASME valves, it is quite common for a figure of 25% to be used.

Two-phase flow - When sizing safety valves for boiling liquids (e.g. hot water) consideration must be given to vaporisation (flashing) during discharge. It is assumed that the medium is in liquid state when the safety valve is closed and that, when the safety valve opens, part of the liquid vaporises due to the drop in pressure through the safety valve. The resulting flow is referred to as two-phase flow.

The required flow area has to be calculated for the liquid and vapour components of the discharged fluid. The sum of these two areas is then used to select the appropriate orifice size from the chosen valve range. (see Example 9.4.3)

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).

Mechatest delivers operator safety and friendly LPG sampling systems that allows for sampling in a safe and controlled environment. To take under high pressure LPG samples the conventional

way is not only inefficient, but in the case of this dangerous media, humans and the environment are subjected to high safety risks, the Mechatest LPG samplers are the safe and efficient

sampling principle, a perfect solution for LPG sampling from tanks, containers, pipeline and reactors, to take representative samples of LPG gas in high pressure

applications. The problem with LPG sampling is that it wants to change state if the pressure varies. This requires a sample system and a sample cylinder with a safe outage tube.

Propane is bought and stored in a liquid form (LPG), and thus fuel energy can be stored in a relatively small space. Compressed natural gas (CNG), largely

Pressure regulators reduce the high pressures of the stored gas in the cylinder to lower pressures that can be safely used in an operating system. Proper regulator selection is critical for both safety and effectiveness of operating systems. Regulators are designed to control pressure; they do not measure or control flow, unless equipped with devices such as a flow meter specifically designed for such purposes.

Regulator connections to cylinder valves must be completely free of dirt, dust, oil, and grease. "Crack" the valve slowly (by opening the valve slightly and then reclosing it) before attaching the regulator in order to blow out dust and debris from the opening. Note: Cylinders containing highly toxic gases should not be "cracked".

Opening a Regulator - Stand on the valve side of the cylinder at arms length so you do not have to reach in front of the regulator face. Turn your head away from the regulator and open the valve, turning counter clockwise, to blow out dust and debris, and then reclose the valve.

Changing a Regulator - Close the valve and drain the regulator by backing out the adjusting screw. Disconnect the regulator, making sure not to touch the nut and gland areas. Connect the regulator to the new cylinder.

Closing a Regulator - Turn the valve clockwise to close the valve. Drain the regulator by turning (opening) the adjusting crew to release any gas. Reclose the adjusting screw.

Recommendation: To provide easier access and additional safety, purchase wall-mounted regulators which connect to the supply cylinder by hose. This will reduce the handling of the regulator and reduce the likelihood of damage.

Diaphragm Valve - This valve uses a two piece stem separated by non-perforated diaphragms. These diaphragms prevent leakage along the valve stem. The lower part of the stem is encased in a spring, which forces the stem away from the seat whent eh valve is opened. The upper stem is threaded into the diaphragm retainer nut. When the handwheel is rotated to the closed position, the upper stem pushes on the diaphragms, which deflect downward, forcing the lower stem against the valve seat. Advantages of this type of valve are that they provide superior leak integrity and have no threads or lubricants in the gas stream to generate particles or contaminants. This type of valve is required for mos

Pressure Relief Valves - A spring-loaded valve opens when the cylinder pressure exceeds the pressure setting of the spring to discharge contents. Once the cylinder pressure decreases to the valve"s pressure setting, the valve will normally reseat without leakage.

Valves for industrial applicationsIn order to prevent the uncontrolled rise in pressure in pressure vessels or pressurized pipelines, a safety valve is inserted. The safety valve is designed so that it opens at a given maximum pressure, thereby relieving the line or the container. Safety valves find their use in almost all areas of the pressure vessel and pipeline construction. In cryogenics as a spring-loaded safety valve for example.