1805P-6358 Instruction Manual

Type 1805P-6358

Instruction Manual Form 5088

Type 1805P-6358 Pilot-Operated Relief Valve Introduction Scope of Manual This manual describes and provides instructions and parts lists for the Type 1805P-6358 pilot operated relief valve. Instructions and parts lists for any other Fisher equipment used with this relief valve will be found in separate manuals.

Product Description The Type 1805P-6358 pilot-operated relief valve is used to provide protection from overpressuring a downstream system. This relief valve is suitable for service on natural gas, air, propane or any other operating medium not corrosive to the internal parts.

Very little buildup over the set pressure is required for the main valve to go wide open for maximum relief capacity. Smooth opening action minimizes system pressure surges during emergency action.

Specifications Table 1 lists Type 1805P-6358 specifications. Some of the specifications for a given relief valve as it comes from the factory appear on a control spring label attached to the Type 6358 pilot spring case and a nameplate attached to the Type 1805P main valve spring case. !

WARNING

W6913

Figure 1. Type 1805P-6358 Pilot-Operated Relief Valve D100675X012

To avoid injury or damage, this relief valve should be installed, operated and maintained in accordance with federal, state and local codes, rules and regulations, and Fisher instructions. Not all

10/97

FISHER-ROSEMOUNT™ Managing The Process Better.™

Type 1805P-6358 Table 1. Specifications Body Size and End Connections 2-inch NPT screwed Maximum Relief (Inlet(1)) Pressure(2) 50 psi (3.4 bar) over relief pressure setting or 110 psig (7.6 bar), whichever is lower Relief Pressure Ranges RELIEF PRESSURE, PSIG (BAR) 10 to 18 (0.7 to 1.2) 18 to 30 (1.2 to 2.0) 30 to 100 (2.0 to 6.9)

PART NUMBER Pilot Spring Main Valve Spring 1B986027212 1F826927052 1B788327022 1F826927052 1K748527202 1D751527022

Representative Wide-Open Flow Coefficients Cg: 900 (without outlet piping) C1: 38

Maximum Temperature Capabilities(2) Standard Elastomers: –20 to 150°F (–29 to 66°C) High Temperature Elastomers: 0 to 300°F (–18 to 149°C) Pressure Registration Relief (inlet) pressure registers internally on main valve diaphragm; an external control line is required for registration of relief pressure on pilot diaphragm Pilot Connections 1/4-inch NPT screwed control line and vent connections Approximate Weight 13 pounds (5.9 kg)

1. Relief pressure plus maximum allowable buildup over setting.

2. None of the pressure/temperature limits in this instruction manual should be exceeded, nor any applicable standard limitation.

codes or regulations permit this valve to be used as a final overpressure protection device. Only a qualified person must install or service the relief valve.

Be certain the nameplate or spring range label is updated to accurately indicate any field changes in equipment, materials, service conditions or pressure settings.

Immediately call a qualified technician in case of trouble. If a leak develops in the system, it indicates that service is required. Failure to correct the situation immediately may create a hazardous condition.

Installation !

WARNING

Personal injury or system damage may result if this relief valve is installed where service conditions could exceed the limits given on the pilot control spring label or main valve nameplate. Installations should be adequately protected from physical damage.

2

Overpressuring any portion of this equipment may cause equipment damage, leaks in the relief valve or personal injury due to bursting of pressurecontaining parts. System operation within table 1 limitations does not eliminate the possibility of damage from external sources or from debris in the gas line. The relief valve should be inspected for damage regularly and after any overpressure condition.

Before installing, inspect the main valve and pilot for any shipment damage and any foreign material.

Make sure that the valve is oriented so that pipeline flow is in the same direction as the arrow on the side of the main valve body. Use a good grade of pipe compound on the pipe threads, but do not put pipe compound on the body threads.

A typical pilot mounting position is shown in figure 1.

However, the pilot may be rotated on the port C pipe nipple (figure 2) so that control and exhaust connections are oriented as desired. A complete Type 1805P-6358 unit requires a control line attached to the 1/4-inch NPT pilot control port D (figure 2).

The control line should be pipe of at least 1/4-inch (6.4 mm) diameter connected to a straight run of inlet piping five to ten pipe diameters upstream from the main valve in a swaged installation, three to five feet (0.9 to 1.5 meters) upstream in an unswaged

Type 1805P-6358 PILOT CONTROL SPRING

A

ADJUSTING SCREW

TYPE 6358

UPPER PORTION OF VALVE PLUG

DIAPHRAGM ASSEMBLY

D LOCKNUT

C

TO MAIN VALVE DIAPHRAGM

HOLLOW PASSAGE IN VALVE PLUG STEM

LOWER PORTION OF VALVE PLUG TO EXHAUST PORT

TYPE 1805P

VALVE GUIDE ORIFICE REGISTRATION HOLE

EXHAUST LINE (MAY BE VENTED TO ATMOSPHERE OR CONNECTED TO MAIN VALVE OUTLET)

INLET (CONTROLLED PRESSURE) LOADING A6919

EXHAUST ATMOSPHERIC PRESSURE

TO VENT STACK

FROM MAIN LINE

A6919

Figure 2. Typical Type 1805P-6358 Relief Valve Installation

installation, or from wherever else the pressure is to be controlled. If the flowing medium is dirty, an appropriate filter in this control line is recommended, or a common filter or strainer can be used in the main or vent line upstream from the control line. !

WARNING

If venting gas will accumulate and be an explosion hazard under enclosed conditions such as in pit or underground installations, make sure the following installation is remotely vented to carry the gas to a safe area.

To avoid possible injury or equipment damage, never adjust the pilot control spring to produce a set pressure higher than the upper limit of the set pressure range for that particular spring.

Install a common 1/4-inch exhaust line into the 1/4-inch NPT pilot exhaust port A. This exhaust line may be vented either directly into the main valve outlet or separately to atmosphere. In either case, a vent line or stack should be of as large a diameter a pipe as practical with a minimum number of bends or other restrictions.

A vent line or stack must be located to avoid venting gas near buildings, air intakes or any hazardous location. The line or stack opening must be protected against debris, weather, condensation, insects or anything else that might clog it.

Set pressure is defined as the pressure at which the main valve starts to discharge. This unit has been designed such that less than a 6 psig (0.4 bar) buildup of the pilot set pressure will assure the main valve to be wide open, and will permit the relief valve to yield full capacity. The set pressure of the unit is adjusted by changing the pilot control spring compression.

3

Type 1805P-6358 Each unit is factory set for the pressure setting specified on the order. If adjustment is necessary, use a pressure gauge to monitor the pressure. Loosen the locknut (figure 2) and turn the pilot adjusting screw clockwise to increase the set pressure or counterclockwise to decrease the set pressure. Then tighten the locknut to maintain the adjustment position.

Maintenance Relief valve parts are subject to normal wear and must be inspected and replaced as necessary. Inspection and maintenance frequency depends upon severity of service conditions. !

Principle of Operation Inlet pressure registers on the underside of the diaphragm of the main valve and enters the pilot through the control line tubing (figure 2), where it registers on the underside of the pilot diaphragm. As long as the inlet pressure is lower than the set pressure, the pilot control spring pushes the pilot valve plug down, closing the exhaust. With the Type 6358 pilot, inlet pressure passes between the diaphragm assembly and the upper portion of the pilot valve plug and into the hollow stem to load the main valve above the diaphragm, keeping it closed.

When the inlet pressure is at set pressure, the diaphragm assembly in the Type 6358 pilot moves upward enough to close off the inlet pressure path into the hollow stem; the exhaust port remains closed by the lower portion of the valve plug. Thus pressure is unable to enter or leave the space above the main diaphragm.

As the inlet pressure rises above set pressure, the pilot diaphragm continues to move upward, opening the exhaust port and allowing pressure on the top of the main valve diaphragm to bleed to atmosphere. The inlet pressure on the bottom of the main valve diaphragm then overcomes the main valve spring force, and the main valve opens, reducing the inlet pressure to set pressure. As the inlet pressure drops below the set pressure, the pilot spring closes the exhaust, and inlet pressure loads the main valve diaphragm casing above and below the diaphragm, allowing the main valve spring to close the main valve.

Keep in mind, the Type 6358 pilot exhaust port stays closed while the main valve is throttling. The pilot bleeds only when it repositions the main valve plug.

4

WARNING

To avoid personal injury or equipment damage, isolate the relief valve from the pressure system and release all pressure from the pilot and main valve before performing maintenance operations.

Type 6358 Pilot Key numbers are referenced in figure 3 unless otherwise noted. The pilot may remain on the pipe nipple during maintenance procedures unless the body assembly (key 1) is replaced or removed for repairs.

Disassembly 1. If necessary to check the outlet end of the body cavity and the seating surfaces for moisture or debris, remove the body plug (key 3) and body plug gasket (key 13) from the body assembly (key 1).

2. Remove the closing cap (key 12), loosen the locknut (key 11), and back out the adjusting screw (key 10) until compression is removed from the control spring (key 7).

3. Remove the machine screws (key 17) and separate the spring case (key 2) from the body assembly (key 1). Remove the control spring seat (key 8), the control spring (key 7).

4. Remove the diaphragm and plug/stem assemblies (key 5 and 4) and make sure the plug/stem guide (key 9) and the hollow passage in the plug stem assembly are not damaged or plugged with moisture or debris.

5. If necessary to replace the diaphragm assembly, the plug/stem assembly, the plug/stem spring (key 14), or the plug/stem O-ring (key 37), remove the connector cap and connector cap gasket (keys 6 and 36) from the top of the diaphragm assembly.

Type 1805P-6358 Assembly

Type 1805P Main Valve

1. If they were removed, install the body plug gasket (key 13) over the body plug (key 3), and then install the body plug into the body assembly.

This procedure is to be performed if inspecting, cleaning, or replacing main valve parts. Key numbers are referenced in figure 4 unless otherwise indicated.

2. Install the plug/stem guide (key 9) if it was removed, making sure that a connector cap gasket (key 36) is installed between the body and the plug/ stem guide.

3. Install the restriction plug (key 20) if it was removed. Coat the threads with sealant (key 41) or equivalent before installation.

4. If replacing the plug/stem O-ring (key 37), sparingly apply Lubriplate lubricant or equivalent to the replacement O-ring and install the O-ring over the plug/ stem assembly (key 4).

5. If they were removed, install the plug/stem assembly and plug/stem spring (keys 4 and 14) into the diaphragm assembly (key 5). Install a replacement connector cap gasket (key 36) on the diaphragm assembly connector, and secure with the connector cap (key 6).

6. Install the diaphragm assembly (key 5) and push down on it to see if the plug/stem assembly (key 4) moves smoothly. The diaphragm assembly should stroke approximately 1/16-inch (2 mm) after the valve plug contacts the port.

Note If installing a control spring of a different range from the one the was removed, be sure to delete the spring range on the spring case and indicate the new spring range.

7. Stack the control spring (key 7), and the control spring seat (key 8) on the diaphragm assembly (key 5).

8. Install the spring case (key 2) on the body (key 1) with the vent assembly (key 16) oriented to prevent clogging or entrance of moisture. Install the machine screws (key 17) and, using a crisscross pattern, torque them to 5 to 7 foot-pounds (7 to 9 N•m).

9. Tighten the locknut (key 11), replace the closing cap gasket (key 19) if necessary, and install the closing cap (key 12).

Note The main valve body (key 1) may remain in the line unless it must be removed for maintenance or replacement. Grease replacement O-rings upon reassembly.

1. Disconnect the lines from pilot ports A and D (figure 2). The pilot may remain attached to the closing cap (key 17) unless this cap will be replaced.

2. Remove the closing cap from the spring case, loosen the locknut (key 15), and turn the set screw (key 14) out until compression is removed from the spring.

3. Unscrew the union nut (key 16) and remove it with the spring case (key 13), spring (key 11), and spring seat (key 12).

4. Pull the O-ring holder (key 4) out of the valve guide orifice (key 2).

5. Remove the diaphragm cap screw (key 10) from the O-ring holder. Take off the diaphragm plate (key 9) and inspect the diaphragm (key 8).

6. Take the machine screw (key 7) out of the opposite end of the O-ring holder, remove the O-ring washer (key 6) and inspect the O-ring (key 5).

7. Remove the valve guide orifice (key 2) from the body and check the Tetra-seal(1) O-ring (key 3).

8. Replace parts as necessary and reassemble the main valve in reverse order of steps 2 through 7. To ensure proper slack in the diaphragm, tighten the union nut finger-tight only. To provide the proper amount of main valve spring loading, turn both the locknut and set screw all the way in until the locknut bottoms against the spring case and the set screw head bottoms against the locknut. Complete the tightening of the union nut and connect the pilot lines.

1. Trademark of Goshen Rubber Company.

5

Type 1805P-6358

A6920

Figure 3. Type 6358 Pilot Asembly

Key

Ordering Parts

5*

When corresponding with a Fisher Representative or the factory concerning this relief valve, include the type number and all other pertinent information stamped on the pilot control spring label and main valve nameplate. Specify the eleven-character part number when ordering new parts from the following parts list.

Parts List Type 6358 Pilot (figure 3) Key

Description Parts Kit (included are keys 4, 5, 13, 14, 19, 36, and 37)

1 2 3 4* 6

Body Assembly, aluminum Spring Case, aluminum Body Plug, aluminum Plug/Stem Assembly, stainless steel/nitrile

Part Number

R6358X00012 39A0138X012 25A6220X012 1B797509032 14B6372X012

6 7

8 9 10 11 12 13* 14 16 17 19 20 36* 37* 41

Description Diaphragm Assembly (includes heat-treated 416 stainless steel diaphragm connector/ nitrile diaphragm) Connector Cap, 18-8 stainless steel Control Spring, Zinc plated steel spring wire 10 to 18 psig (0.7 to 1.2 bar) 18 to 30 psig (1.2 to 2.0 bar) 30 to 100 psig (2.0 to 6.9 bar) Control Spring Seat, pl steel Plug/Stem Guide, stainless steel Adjusting Screw, pl steel Locknut, Zn pl steel Closing Cap, plastic Body Plug Gasket, composition Plug/Stem Spring, stainless steel Type Y602-12 Vent Assembly, plastic Machine Screw, carbon steel (6 req'd) Closing Cap Gasket, composition Restriction Plug, pl carbon steel Connector Cap Gasket, Fluoroelastomer (2 req'd) Plug/stem O-ring, nitrile rubber Anti-Seize Compound, zinc plated

Part Number

15A6216X072 16A2921X012 1B986027212 1B788327022 1K748527202 1B798525062 16A2923X012 10B7192X012 1A946324122 23A6220X012 1C495704022 1E701337022 27A5516X012 1H421728992 15A6218X012 1V743528982

1U1716X0012 16A2920X012 1M52406992

Type 1805P-6358

BE9481-C B1128

Figure 4. Type 1805P Main Valve Asembly

Type 1805P Main Valve (figure 4) Key 1 2 3* 4 5*

6 7 8*

9

Description

Part Number

Valve Body, 2-inch NPT, cast iron Valve Guide Orifice, anodized aluminum Tetra-seal O-ring, nitrile O-ring Holder, aluminum

1E824319012 1N939909012 1N940306562 1E824609092

O-ring Nitrile (standard) Fluoroelastomer (high temperature) O-ring Washer, stainless steel Machine Screw, steel

1C562206992 1N285406382 1E824235072 1B420428982

Diaphragm Nitrile (standard) Fluoroelastomer (high temperature) Diaphragm Plate, brass

1E824102052 1E8241X0022 1E824714012

Key

Description

Part Number

10

Cap Screw, steel

11

Spring, steel, Cd pl 10 to 30 psig (0.7 to 2.0 bar) 30 to 100 psig (2.0 to 6.9 bar)

1F826927052 1D751527022

12 13 14

Spring Seat, steel Spring Case, cast iron Set Screw, steel, Cd pl

1D667125072 2E824919042 1D995448702

15 16 17

Locknut, steel, Cd pl Union Nut, ductile iron Closing Cap, brass

1H483324122 1E766619062 1E823914012

18 19

Nameplate, aluminum Drive Screw, steel (4 req'd)

1E2401X0042 1E501728982

1E760324052

7

Type 1805P-6358

Fisher, Fisher-Rosemount, and Managing The Process Better are marks owned by Fisher Controls International, Inc. or Fisher-Rosemount Systems, Inc. All other marks are the property of their respective owners. ©Fisher Controls International, Inc., 1977, 1997; All Rights Reserved

The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. We reserve the right to modify or improve the designs or specifications of such products at any time without notice.

For information, contact Fisher Controls: Marshalltown, Iowa 50158 USA 28320 Gallardon, France Sao Paulo 05424 Brazil Singapore 128461 Printed in U.S.A.

FISHER-ROSEMOUNT Managing The Process Better.