crosby safety valve manual factory

Crosby Catalog No. 310 310 310 307 902 902

(c) The spring in a safety valve or safety relief valve shall pressure which opens in proportion to the increase in pressure over the opening pressure. A

not be set for any pressure more than 5% above or below safety relief valve is a pressure relief valve characterized by rapid opening or pop action, or by

that for which the valve is marked, unless the setting is application. A pilot operated pressure relief valve is a pressure relief valve in which the major

within the spring design range established by the valve relieving device is combined with and is controlled by a self-actuated auxiliary pressure relief

assembler, and a valve data tag shall be provided that Rupture disks may be designed in several configurations, such as plain flat, prebulged or

identifies the set pressure, capacity and date. The valve reverse buckling, and may be made of either ductile or brittle material; rupture disk material

or safety relief valve and the rupture disk device is ample appropriate allowance for any structual members which may reduce the net flow area through

(2) the stamped capacity of a spring loaded carefully evaluated to ensure that the media being handled and the valve operational

and the vessel shall be multiplied by a factor of 0.90 of the builds up in the space between the disk and the safety or safety relief valve which will occur

the capacity of such a combination shall be established in to minimize the loss by leakage through the valve of valuable or of noxious or otherwise

valve may be established in accordance with the appro- pressure if back pressure builds up in the space between the valve and rupture disk. A

EMERSON. CROSBY H-SERIES DIRECT SPRING SAFETY VALVESDirect spring safety valves that provide comprehensive overpressure protection for ASME Boiler and Pressure Vessel Code Section I, and Section VIII steam safety applicationsFEATURES HCI ISOFLEX" • ASME/NB certified capacities for steam. • Set and tested on steam. • Full nozzle flanged option. • Restricted lift for customized capacity. • Long service life. • Low maintenance. • Two ring set pressure and blowdown control. • ISOFLEX seat tightness up to 93%. For seat tightness greater than 93% consult factory. TECHNICAL DATA GENERAL APPLICATION H-Series direct spring operated safety valves are the proven solution for comprehensive overpressure protection on steam safety applications including economizers, steam drums, superheaters, reheaters and more. Sizes: Orifices: Connections: Temperature range: Set pressures: IVi" F IV2" to 6" RR 10" 0.307 to 19.29 in2 (1.98 to 124.45 cm2) Flanged or welded inlet 1120 °F (604 °C) 15 to 5000 psig (1 to 345 barg) Code: ASME Boiler and Pressure Vessel Code Section I, and Section VIII Emerson.com/FinalControl © 2017 Emerson. All Rights Reserved VCTDS-00595-EN 17/11

Complete overpressure protection for ASME B&PVC Section I A complete safety valve package for utility and industrial steam generators and steam systems. • Boilers with design pressures to 3000 psig (207 barg). • Valves designed to increase plant up-times, extend maintenance intervals and increase total valve life. Steam System Components 7. Boiler feed water pump 8. Cold reheat inlet VALVE SELECTION APPLICATIONS AND RECOMMENDED™ VALVE SELECTION NOTES 1. Selection matrix shows valves in optimum locations - Styles HSJ and HCI may be interchanged to suit a specific application or to obtain a...

STYLE HE ISOFLEX® Style HE ISOFLEX® safety valves are high pressure, high capacity reaction type valves designed specifically for saturated steam service on boiler drums with design pressures above 2000 psig (138 barg) up to critical pressure. FEATURES TECHNICAL DATA • Extends Up-time - ISOFLEX® seat tightness to 93% of set pressure ensures maximum generating times, extending maintenance intervals. For seat tightness greater than 93% consult factory. • Reduces Maintenance Costs - Exceptional seat tightness minimizes maintenance resources and repair times and reduces spare parts purchase and...

PRODUCT OVERVIEW The HE ISOFLEX incorporates our latest field proven seat tightness design which allows boilers to operate close to set pressure without leakage across the valve seat. The HE ISOFLEX also has a unique patented eductor control that permits the valve to attain full capacity lift at a pressure 3% above popping pressure to the requirements of Section I of the ASME Boiler and Pressure Vessel Code. APPLICATION The HE ISOFLEX safety valve is a high pressure, high capacity reaction type valve, designed specifically for saturated steam service on boiler drums having design pressures...

CROSBY H-SERIES STYLE HE ISOFLEX 28 Part name Body Nozzle Nozzle ring Nozzle ring set screw Disc insert Disc holder Disc holder retaining nut Eductor Guide ring Guide ring set screw Spindle assembly Piston Piston retaining ring Spindle nut Bonnet Bonnet studs Bonnet stud nuts Material Carbon steel SA-216 Gr. WCC Stainless steel Stainless steel Stainless steel Inconel® Nickel alloy Stainless steel Nickel alloy Stainless steel Stainless steel Stainless steel Nickel alloy Steel Steel Carbon steel SA-216 Gr. WCC Alloy steel SA-193 Gr. B7 Steel SA-194 Gr. 2H Bottom spring washer Top spring...

2500 psig maximum pressure 1. These style designations are for standard welded inlets. For optional CL 2500 flanged inlet valves, the "W" is dropped from the style designation. 2. Weld prep per customer"s specifications. Safety valves must be mounted on a nozzle with an inlet diameter equal to or greater than the nominal valve inlet size, dimension A. See ASME boiler and pressure vessel code Section I and ANSI/ASME B31.1 for recommended installation. 3. Bolt holes straddle centerline on flanged connections. 4. Dismantling height: an additional 20 inches (508 mm) is required. Drain: main...

1 Increases Operating Efficiency Sizes: - Restricted Lift Option for customized capacity, reduced reaction forces, and boiler design standardization Orifices: - Seat tightness up to 93% of valve set pressure. For seat tightness greater than Connections: 93% consult factory - Two ring control to adjust overpressure and Maximum blowdown independently temperature: - May also be used for ASME Boiler and Maximum Pressure Vessel Code Section VIII off boiler set pressure: steam applications for higher operating Codes: pressures 1 Reduces Maintenance Costs CROSBY H-SERIES STYLE HCI ISOFLEX DIRECT...

CROSBY H-SERIES STYLE HCI ISOFLEX PRODUCT OVERVIEW The HCI ISOFLEX safety valve is a high capacity nozzle type valve suitable for saturated and superheated steam service. The valves are available in inlet sizes of 1½”, 2", 2½”, 3", 4" and 6" and in orifice sizes H2 to RR specifically designed for the power industry. Welded inlets and flanged outlets are standard, with flanged inlets (1) with full (removable) nozzles (2) also available. Blowdown control is precise with two adjustable rings (3 and 12) - one each on the nozzle (1B or 2) and guide (11). Blowdown may be adjusted from 2 to 4%...

Emerson recommends that sufficient inventory of spare parts be maintained to support process requirements. Always be sure to use genuine Emerson parts to ensure continued product performance and warranty. NOTES A complete set of spare cotter pins (not listed above) is also recommended for proper maintenance of the valve.

CROSBY SERIES HE ISOFLEX SELF-ACTUATED SAFETY VALVES ® INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS Installation NOTE 1 TO FIGURE 2A • Inlet piping Delivered with the body and packaged in small bag are Many valves are damaged when first placed the following: in service because of failure to clean the One O-ring (for hydrostatic test) connections properly before installation.

CROSBY SERIES HE ISOFLEX SELF-ACTUATED SAFETY VALVES ® INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS CAUTION • Initial field assembly procedures (Prior to installing superstructure) It is possible to thread the adjusting ring too high onto the eductor NOTE (9). If this happens when the valve is assembled, It is recommended that upon completion of all the disc holder (6) will load on the guide ring (10) hydrostatic tests on new installations, a Crosby service...

CROSBY SERIES HE ISOFLEX SELF-ACTUATED SAFETY VALVES ® INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS Valve disassembly CAUTION • Removal of the lifting gear This device has a limited piston stroke that should Remove the forked lever pin (34), forked lever not be exceeded. If the piston stroke is exceeded, (33), cap (28), spindle nut cotter and spindle nut the second notch on the piston (2) will be above (15).

CROSBY SERIES HE ISOFLEX SELF-ACTUATED SAFETY VALVES ® INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS 1.a Check ring settings - Check the lapping block frequently on a good lapping block conditioner to make certain that it is perfectly flat on both sides. If considerable lapping is required, spread Spindle (12) a thin coat of medium lapping compound on...

CROSBY SERIES HE ISOFLEX SELF-ACTUATED SAFETY VALVES ® INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS LAPPING COMPOUNDS Abrasive Grit size Average micron size Description Manufacturer’s trade name or equivalent Silicon carbide Medium coarse U.S. products no.2F Crystolen Silicon carbide Medium U.S. products no.3F Crystolen Silicon carbide Fine U.S.

Many electronic, pneumatic and hydraulic systems exist today to control fluid system variables, such as pressure, temperature and flow. Each of these systems requires a power source of some type, such as electricity or compressed air in order to operate. A pressure Relief Valve must be capable of operating at all times, especially during a period of power failure when system controls are nonfunctional. The sole source of power for the pressure Relief Valve, therefore, is the process fluid.

Once a condition occurs that causes the pressure in a system or vessel to increase to a dangerous level, the pressure Relief Valve may be the only device remaining to prevent a catastrophic failure. Since reliability is directly related to the complexity of the device, it is important that the design of the pressure Relief Valve be as simple as possible.

The pressure Relief Valve must open at a predetermined set pressure, flow a rated capacity at a specified overpressure, and close when the system pressure has returned to a safe level. Pressure Relief Valves must be designed with materials compatible with many process fluids from simple air and water to the most corrosive media. They must also be designed to operate in a consistently smooth and stable manner on a variety of fluids and fluid phases.

The basic spring loaded pressure Relief Valve has been developed to meet the need for a simple, reliable, system actuated device to provide overpressure protection.

The Valve consists of a Valve inlet or nozzle mounted on the pressurized system, a disc held against the nozzle to prevent flow under normal system operating conditions, a spring to hold the disc closed, and a body/Bonnet to contain the operating elements. The spring load is adjustable to vary the pressure at which the Valve will open.

When a pressure Relief Valve begins to lift, the spring force increases. Thus system pressure must increase if lift is to continue. For this reason pressure Relief Valves are allowed an overpressure allowance to reach full lift. This allowable overpressure is generally 10% for Valves on unfired systems. This margin is relatively small and some means must be provided to assist in the lift effort.

Most pressure Relief Valves, therefore, have a secondary control chamber or huddling chamber to enhance lift. As the disc begins to lift, fluid enters the control chamber exposing a larger area of the disc to system pressure.

This causes an incremental change in force which overcompensates for the increase in spring force and causes the Valve to open at a rapid rate. At the same time, the direction of the fluid flow is reversed and the momentum effect resulting from the change in flow direction further enhances lift. These effects combine to allow the Valve to achieve maximum lift and maximum flow within the allowable overpressure limits. Because of the larger disc area exposed to system pressure after the Valve achieves lift, the Valve will not close until system pressure has been reduced to some level below the set pressure. The design of the control chamber determines where the closing point will occur.

A safety Valve is a pressure Relief Valve actuated by inlet static pressure and characterized by rapid opening or pop action. (It is normally used for steam and air services.)

A low-lift safety Valve is a safety Valve in which the disc lifts automatically such that the actual discharge area is determined by the position of the disc.

A full-lift safety Valve is a safety Valve in which the disc lifts automatically such that the actual discharge area is not determined by the position of the disc.

A Relief Valve is a pressure relief device actuated by inlet static pressure having a gradual lift generally proportional to the increase in pressure over opening pressure. It may be provided with an enclosed spring housing suitable for closed discharge system application and is primarily used for liquid service.

A safety Relief Valve is a pressure Relief Valve characterized by rapid opening or pop action, or by opening in proportion to the increase in pressure over the opening pressure, depending on the application and may be used either for liquid or compressible fluid.

A conventional safety Relief Valve is a pressure Relief Valve which has its spring housing vented to the discharge side of the Valve. The operational characteristics (opening pressure, closing pressure, and relieving capacity) are directly affected by changes of the back pressure on the Valve.

A balanced safety Relief Valve is a pressure Relief Valve which incorporates means of minimizing the effect of back pressure on the operational characteristics (opening pressure, closing pressure, and relieving capacity).

A pilotoperated pressure Relief Valve is a pressure Relief Valve in which the major relieving device is combined with and is controlled by a self-actuated auxiliary pressure Relief Valve.

A poweractuated pressure Relief Valve is a pressure Relief Valve in which the major relieving device is combined with and controlled by a device requiring an external source of energy.

A temperature-actuated pressure Relief Valve is a pressure Relief Valve which may be actuated by external or internal temperature or by pressure on the inlet side.

A vacuum Relief Valve is a pressure relief device designed to admit fluid to prevent an excessive internal vacuum; it is designed to reclose and prevent further flow of fluid after normal conditions have been restored.

Many Codes and Standards are published throughout the world which address the design and application of pressure Relief Valves. The most widely used and recognized of these is the ASME Boiler and Pressure Vessel Code, commonly called the ASME Code.

is the calculated mass flow from an orifice having a cross sectional area equal to the flow area of the safety Valve without regard to flow losses of the Valve.

the pressure at which a Valve is set on a test rig using a test fluid at ambient temperature. This test pressure includes corrections for service conditions e.g. backpressure or high temperatures.

is the value of increasing static inlet pressure of a pressure Relief Valve at which there is a measurable lift, or at which the discharge becomes continuous as determined by seeing, feeling or hearing.

Because cleanliness is essential to the satisfactory operation and tightness of a safety Valve, precautions should be taken during storage to keep out all foreign materials. Inlet and outlet protectors should remain in place until the Valve is ready to be installed in the system. Take care to keep the Valve inlet absolutely clean. It is recommended that the Valve be stored indoors in the original shipping container away from dirt and other forms of contamination.

Safety Valves must be handled carefully and never subjected to shocks. Rough handling may alter the pressure setting, deform Valve parts and adversely affect seat tightness and Valve performance.

When it is necessary to use a hoist, the chain or sling should be placed around the Valve body and Bonnet in a manner that will insure that the Valve is in a vertical position to facilitate installation.

Many Valves are damaged when first placed in service because of failure to clean the connection properly when installed. Before installation, flange faces or threaded connections on both the Valve inlet and the vessel and/or line on which the Valve is mounted must be thoroughly cleaned of all dirt and foreign material.

Because foreign materials that pass into and through safety Valves can damage the Valve, the systems on which the Valves are tested and finally installed must also be inspected and cleaned. New systems in particular are prone to contain foreign objects that inadvertently get trapped during construction and will destroy the seating surface when the Valve opens. The system should be thoroughly cleaned before the safety Valve is installed.

The gaskets used must be dimensionally correct for the specific flanges. The inside diameters must fully clear the safety Valve inlet and outlet openings so that the gasket does not restrict flow.

For flanged Valves, draw down all connection studs or bolts evenly to avoid possible distortion of the Valve body. For threaded Valves, do not apply a wrench to the Valve body. Use the hex flats provided on the inlet bushing.

Safety Valves are intended to open and close within a narrow pressure range. Valve installations require accurate design both as to inlet and discharge piping. Refer to International, National and Industry Standards for guidelines.

The Valve should be mounted vertically in an upright position either directly on a nozzle from the pressure vessel or on a short connection fitting that provides a direct, unobstructed flow between the vessel and the Valve. Installing a safety Valve in other than this recommended position will adversely affect its operation.

Discharge piping should be simple and direct. A "broken" connection near the Valve outlet is preferred wherever possible. All discharge piping should be run as direct as is practicable to the point of final release for disposal. The Valve must discharge to a safe disposal area. Discharge piping must be drained properly to prevent the accumulation of liquids on the downstream side of the safety Valve.

The weight of the discharge piping should be carried by a separate support and be properly braced to withstand reactive thrust forces when the Valve relieves. The Valve should also be supported to withstand any swaying or system vibrations.

If the Valve is discharging into a pressurized system be sure the Valve is a "balanced" design. Pressure on the discharge of an "unbalanced" design will adversely affect the Valve performance and set pressure.

The Bonnets of balanced bellows safety Valves must always be vented to ensure proper functioning of the Valve and to provide a telltale in the event of a bellows failure. Do not plug these open vents. When the fluid is flammable, toxic or corrosive, the Bonnet vent should be piped to a safe location.

It is important to remember that a pressure Relief Valve is a safety device employed to protect pressure vessels or systems from catastrophic failure. With this in mind, the application of pressure Relief Valves should be assigned only to fully trained personnel and be in strict compliance with rules provided by the governing codes and standards.