Farris engineering 1890 series User manual

Technical Manual 296T

Series

1890 & 2850

Maintenance

Manual

Farris Engineering

Division of Curtiss-Wright Flow Control Corporation

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Table of Contents

(Manual Revision 1, August 1998)

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 1

2. Disassembly

Series 2850 and 2852 . . . . . . . . . . . . . . . . . . . . .Page 2

Series 1890 and 1892 . . . . . . . . . . . . . . . . . . . . .Page 3

3. Lifting Lever Assemblies

Open Lifting Lever . . . . . . . . . . . . . . . . . . . . . . . .Page 4

Packed Lifting Lever . . . . . . . . . . . . . . . . . . . . . .Page 4

4. Lapping Procedure . . . . . . . . . . . . . . . . . . . . . . .Page 5

5. Assembly

Series 2850 and 2852 . . . . . . . . . . . . . . . . . . . . .Page 6

Series 1890 and 1892 . . . . . . . . . . . . . . . . . . . . .Page 6

6. Testing and Setting . . . . . . . . . . . . . . . . . . . . . . .Page 7

Appendix A: Critical Seat Dimensions . . . . . . . . . .Page 8

10195 BRECKSVILLE ROAD

BRECKSVILLE, OHIO 44141 US A

PHONE: (440) 838-7690

FAX: (440) 838-7699

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1. Introduction

This manual contains sufficient information

to allow trained maintenance personnel to

properly repair types 1890, 1892, 2850,

and 2852 pressure relief valves.

All of the assembly and disassembly

instructions refer to types with plain

screwed caps. When repairing types with

either open or packed lifting levers, refer

to Section 3 which describes the removal

of the appropriate lever assembly.

If a valve repair requires replacement

parts, only factory-supplied components

shall be used. Use of parts from other

than the original manufacturer will lead

to potentially dangerous operating condi-

tions. If faced with repairs exceeding the

scope of this manual, contact the Farris

Factory.

Farris Engineering

Division of Curtiss-Wright Flow Control Corporation

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2. Disassembly

When a valve is first received in the shop, it should

be given a visual inspection to note its condition

when removed from service. The valve should

then be carefully dismantled. Proper facilities and

tools should be available. At each stage in the dis-

mantling process, visually inspect all parts of the

valve for evidence of wear and corrosion. If parts

are worn, replace them.

Series 2850 and 2852 (Fig. 2.1)

1. Mount valve vertically in a vise utilizing the flats

in the body.

2. Remove wire seal. Unscrew cap by turning

counterclockwise. Remove cap gasket. (For

open lever and packed lever cap construction,

refer to the section on Lifting Lever

Assemblies.)

3. Measure the distance from the top of the spring

adjusting screw to the top of the bonnet. Use

this measurement when reassembling the valve

to approximately duplicate the original set

pressure.

4. Loosen the jam nut.

5. Relieve the spring compression by turning the

spring adjusting screw counterclockwise.

6. Remove blowdown ring lock screw and gasket.

7. Thread a pipe into the outlet and turn the bon-

net counterclockwise. Lift the bonnet off to

expose internal subassembly.

8. Remove the upper spring button, spring and

lower spring button from the stem.

9. Remove the stem shoulder. Stem shoulder ring

may be a one-piece clip or split rings. Be care-

ful during disassembly; split rings may fall free.

Current valves do not use a stem shoulder and

split ring. The stem shoulder is an integral part

of the stem.

10. Lift the stem with the disc attached. If desired,

remove the grooved pin and lift the stem from

the disc.

11. Unscrew the blowdown ring from the body.

12. Clean all parts and threaded surfaces thor-

oughly. Replace all gaskets. Lap the body

seat and disc surfaces. (See the section on

Lapping for details.)

Bill of Materials

Farris Engineering

Division of Curtiss-Wright Flow Control Corporation

Item Part Name Material

2850 & 2852 2850/S4 & 2852/S4

SA-479 Type 316 SA-479 Type 316

1 Body St. St. or SA-351 St. St. or SA-351

Gr. CF8M St. St. Gr. CF8M St. St.

SA-216 Gr. WCB SA-351 Gr. CF8M

2 Bonnet Carbon Steel St. St.

3 Disc 316 St. St. 316 St. St.

4 Blowdown Ring 316 St. St. 316 St. St.

5 Cap Carbon Steel 316 St. St.

6 Stem 316 St. St.

7 Spring Adj. Screw 316 St. St.

8 Jam Nut 316 St. St.

9 Upper Spring Button 316 St. St.

10 Lower Spring Button 316 St. St.

11 Cap Gasket 316 St. St.

12 Stem Shoulder 316 St. St.

13 Blowdown Ring 316 St. St.

Lockscrew

14 Grooved Pin 316 St. St.

15 Stem Shoulder Ring St. St. 316 St. St.

16 Wire Seal St. St. Wire/Lead Seal

17 Nameplate (not shown) Stainless Steel

18 Spring See Spring Table

19 Blowdown Ring 316 St. St.

L/S Gasket

Valve No. Spring Material

2850 316 Stainless Steel

2852 Chrome Alloy, Rust Proofed

2850/S4 316 Stainless Steel

2852/S4 Chrome Alloy, Nickel Plated

SpringTable

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1. Mount valve vertically in a vise utilizing the flats

in the body.

2. Remove wire seal. Unscrew cap by turning

counterclockwise. Remove cap gasket. (For

open lever and packed lever cap construction,

refer to the section on Lifting Lever

Assemblies.)

3. Measure the distance from the top of the spring

adjusting screw to the top of the bonnet. Use

this measurement when reassembling the valve

to approximately duplicate the original set pres-

sure.

4. Loosen the jam nut.

5. Relieve the spring compression by turning the

spring adjusting screw counterclockwise.

6. Thread a pipe into the outlet and turn the bon-

net counterclockwise. Lift the bonnet off to

expose internal subassembly.

7. Lift the stem with spring and buttons attached.

Remove upper spring button, spring and lower

spring button.

8. Remove the lift stop ring from the guide.

9. By inverting the assembly, remove the disc from

the guide.

10. Unscrew the guide from the valve body Re-.

move body gasket.

11. Clean all parts and threaded surfaces tho-

roughly. Replace all gaskets. Lap the body

seat and disc surfaces. (See the section on

Lapping for details.)

Fig 2.2

1890 &1892

Series

Series 1890 and 1892 (Fig. 2.2)

Farris Engineering

Division of Curtiss-Wright Flow Control Corporation

Bill of Materials

Item Part Name Material

1890 & 1892 1890/S4 & 1892/S4

SA-479 Type 316 SA-479 Type 316

1 Body St. St. St. St.

SA-216 Gr. SA-351 Gr.

2 Bonnet WCB Carbon Steel CF8M St. St.

3 Disc 316 St. St. 316 St. St.

4 Guide St. St. 316 St. St.

5 Cap, Plain Screwed Carbon Steel 316 St. St.

6 Stem St. St. 316 St. St.

7 Spring Adj. Screw St. St. 316 St. St.

8 Sprin Button St. St. 316 St. St.

9 Jam Nut St. St. 316 St. St.

10 Stem Shoulder St. St. 316 St. St.

11 Body Gasket Flexible Graphite 316 St. St.

12 Cap Gasket Flexible Graphite 316 St. St.

13 Lift Stop Ring St. St. St. St.

14 Retaining Ring - St. St. St. St.

Stem Shoulder

15 Wire Seal St. St. Wire/Lead Seal

16 Nameplate (not shown) Stainless Steel

17 Spring See Spring Table

Lap Joint Stub End SA-403 Gr. SA-403-Gr.

(Inlet) WP 316 St. St. WP 316 St. St.

N Lap Joint Stub End SA-234 SA-403-Gr.

O(Outlet) Carbon Steel WP 316 St. St.

TLap Joint Flange SA-181 or SA-105 SA-182-Gr.

E (Inlet) Carbon Steel F316 St. St.

Lap Joint Flange SA-181 or SA-105 SA-182-Gr.

(Outlet) Carbon Steel F316 St. St.

Valve No. Spring Material

1890 316 Stainless Steel

1892 Chrome Alloy, Rust Proofed

1890/S4 316 Stainless Steel

1892/S4 Chrome Alloy, Nickel Plated

SpringTable

Note: Items not shown are applicable to the F 1890 Series (Flanged)

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3. Lifting Lever Assemblies

A. OPEN LIFTING LEVER (Fig. 3.1)

1. Remove wire seal and cotter pin. Slide out button head

rivet to release lever from cap.

2. Remove set screw from base of cap and lift cap off

bonnet.

3. Remove stem jam nut and stem test washer from the

stem.

4. Clean all parts and reassemble in reverse order. Adjust

stem test washer so there is 1/8” clearance between

test lever fulcrum and stem test washer.

B. PACKED LIFTING LEVER

There are several designs of packed cap constructions.

Refer to the appropriate section below for your particu-

lar cap construction.

(a) Fig. 3.2

1. Remove groove pin from lever and slide lever off the

cam

shaft.

2. Remove gland from gland nut. Unscrew gland nut from

bonnet and remove packing ring and cam. If any signs

of leakage exist, replace packing ring.

3. Break wire seal and unscrew cap from bonnet. Holding

the stem with pliers, remove stem jam nut and stem test

washer.

4. Reassemble in reverse order making sure the camshaft

lobe is pointing down. The stem test washer should be

adjusted to ensure the cam will make contact with the

stem test washer and lift the stem when the lever is

actuated.

(b) Fig. 3.3

Remove groove pin from lever and slide lever off the

cam shaft.

2. Complete disassembly is only required if the packing

ring is to be replaced or internal inspection is required.

To remove assembly, rotate the lever down and

unscrew the cap.

3. To complete disassembly, remove the gland, packing

ring and retaining ring.

Pull the cam shaft from the cap. The cam can then be

removed through the bottom of the cap.

5. Remove the stem jam nut and stem test washer.

Reassemble in reverse order, making sure the cam

rests beneath the stem test washer.

Remove lever jam nut and washer. Slide lever off the

cam shaft.

2. Follow steps 2 to 6 in section (b).

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5. (1890 and 1892 only) Measure and record the body seat

height. Remove the same thickness of material from the

bottom face of the guide as that has been lapped off

from the body seat.

6. Carefully clean compound from all parts. Failure to do so

may foul the seat and disc surfaces. When reinstalling

the parts in the valve and/or in assembling the disc in the

guide, be careful not to scratch or score either surface.

7. Check Appendix A for critical seat dimensions. Replace

any parts that have dimensions smaller than the mini-

mum required.

4. Lapping Procedure

(For metal seats only; does not apply to O-ring seat seal

valve)

1. The finish on the body seat and disc are critical to seat

tightness. After the parts have been cleaned, both parts

should be lapped to remove all blemishes and score

marks. This can be done on an automatic lapping

machine or by hand using a cast iron lapping block or

Pyrex lapping glass which is known to have a perfectly

flat surface.

PYREX LAPPING PLATES

PART NO. MAT. CODE SIZE THICKNESS

7688 164 1-1/2″l/4″

7689 164 2-1/4″3/8″

2. Use Farris 1200 lapping compound. When lapping the

disc, operate with a light figure eight motion over entire

block surface. In this way complete contact will be

made. With this motion the complete surface of the

part will be evenly lapped and you will avoid wearing a

groove in the block.

3. Lap the disc until all blemishes and score marks have

been removed. As the figure eight motion is executed,

frequently lift the disc away from the block to get a

fresh bite on the compound. Most importantly, do not

contaminate compounds with dirt. Store lapping blocks

and lapping glass in a clean, dust-free area.

4. Follow the same procedure for lapping the body seat.

When lapping bodies, the body can be placed on a

table and a lapping block placed on the body. Be sure

that the lapping block does not tip over the side of the

body (which would cause rounding of the edges). Use a

light, rapid figure eight stroke, lifting the block from the

body occasionally.

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5. Assembly

Series 2850 and 2852

1. Refer to Figure 2.1 for construction details.

2. Visually inspect all parts to be assembled. Replace gas-

kets, O-rings, and any parts that are worn. Lubricate all

threaded and mating surfaces with Bostik Never Seez

(or equivalent).

3. Examine seat of body and disc for any marks that may

cause leakage. Refer to the section on Lapping if relap-

ping is necessary.

4. (O-ring Seat Only) Refer to Fig. 5.1. Position the disc on

a flat surface with the O-ring groove facing up. Insert

O-ring into the disc groove. Insert the O-ring retainer

on the disc, ensuring the O-ring is centered. Lock the

O-ring and retainer to the disk with the hex nut.

5. Screw blowdown ring onto the body.

6. Place stem into the disc. Drive grooved pin through the

disc into the stem if grooved pin has been disassem-

bled.

7. Place disc stem assembly over the body, making sure

that the disc and body seats are aligned.

8. Place stem shoulder over stem shoulder ring.

9. Install lower spring button, spring and upper spring but-

ton on stem.

10. Place bonnet over the assembled parts and screw

down onto the body.

11. Thread the jam nut onto the spring adjusting screw.

12. Thread spring adjusting screw into bonnet to the posi-

tion recorded during disassembly.

13. With a screwdriver, turn blowdown ring up until it

touches the disc. Then back off the number of notch-

es indicated below.

14. Screw blowdown ring lock screw into bonnet. Adjust

blowdown ring lock screw to engage blowdown ring

notches without jamming the ring in its tightened posi-

tion.

15. The valve is now ready to be removed for testing.

Series 1890 and 1892

1. Refer to Figure 2.2 for construction details.

2. Visually inspect all parts to be assembled. Replace all

gaskets. Lubricate all threaded and mating surfaces

with Bostik Never Seez (or equivalent).

3. Examine seat of body and disc for any marks or surface

imperfections that may reduce seat tightness. If relap-

ping is necessary, refer to the section on Lapping.

4a.(Metal Seat Only) Loosely assemble body and guide.

Insert disc in guide and verify that guide turndown from

disc contact is 1/16 to 1/4 turn. For set pressure under

100 psig, 1/8 turndown maximum is required. Remove

disc.

4b.(O-Ring Seat Only) It is recommended that

O-ring/disc

subassembly be replaced rather than attempt removal

of retaining ring. Do not use a metal seat guide in

O-ring seat seal valves.

5. Tighten guide to body with 1/4” dia. bar inserted

through

guide exit holes with approximate torque of 20 ft. Ibs.

6. Insert disc and install lift stop. Verify that available disc

lift is greater than .085”.

7. Place stem shoulder over retaining ring. Install spring

and spring buttons on stem and insert entire assembly

into bonnet/spring adjusting screw subassembly. The

lower subassembly with body gasket can then be

assembled and tightened to approximately 40 ft. Ibs.

torque.

8. Hand tighten adjusting screw until slight spring com-

pression occurs.

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Division of Curtiss-Wright Flow Control Corporation

INLET SIZE # NOTCHES

3/4″6

1, 1 1/2″22

2, 3″33

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WATER - Before starting the seat tightness test, the outlet

body bowl shall be filled with water, and the valve shall be

allowed to stabilize with no visible flow from the valve out-

let. The valve shall be observed for 1 minute at the test

pressure. There shall be no visible leakage at the valve

outlet.

Soft SeatedValves:

Soft seated valves shall be tested at 95% of set pressure

when set above 100 psig; they shall be tested at 5 psig

below set pressure when the set pressure is less than or

equal to 100 psig.

AIR - There shall be no leakage (zero bubbles) using the

test method outlined above.

STEAM and WATER - There shall be no visible leakage at

the valve outlet.

2. If any valve fails to meet leakage requirements, it shall

be reworked.

3. Assemble appropriate cap construction after leak tight-

ness has been verified. If valve type is open lever, no

back pressure test is required. Plain cap and packed

lever valves must be back pressure tested as outlined

in the next section.

BACK PRESSURETEST

1. This test applies to all valves designed for discharge to

a closed system (plain or packed lever cap construc-

tion) with inlet sizes larger than 1 nps.

2. The secondary pressure zone of the valve shall be test-

ed with air or other suitable gas at a pressure of at least

30 psi. The valve should be pressurized at the outlet

with shop air or other means. A soap solution or other

suitable solution shall be applied to all connections

which are potential leakage paths (i.e., body/bonnet

connection, cap/bonnet connection, packed lever

assembly/cap connection). No leakage is acceptable.

3. If leakage is detected at any location, the valve shall be

reworked.

6. Setting & Testing

TESTING AND SETTING PROCEDURE

1. Mount the valve on the test stand. Use air as the test

medium for air, gas and vapor or flashing service appli-

cations. Set valves for saturated steam service on satu-

rated steam. Valves for steam service set with air

should include temperature compensation. The name-

plate provides “Cold Differential Test Pressure.” Set

valves for liquid service on water.

2. Hold the stem tightly and tighten (turn clockwise) the

spring adjusting screw to increase the spring force.

Make sure the stem does not rotate while loading the

spring.

3. Slowly raise the test drum pressure and observe the

opening point. The set pressure on air or steam is the

“pop point” while on water it is the first continuous flow.

4. If necessary reduce the test drum pressure and adjust

the spring adjusting screw. Repeat this until the valve

opens at the required pressure, designated as “Cold

Differential Test Pressure.” At the desired setting, torque

the jam nut to 25 ft. lbs. and assemble cap and gasket

for tightness testing. Check set point once more after

locking jam nut.

Never adjust the spring setting when the pressure

under the valve is near its popping point, as the body

seat and disc seat might score and/or gall. Always

lower the pressure in the valve at least 25 percent

below popping pressure before making adjustments.

This will put a loading on the seat surfaces, and pre-

vent rotation and damage.

SEAT TIGHTNESSTESTING

WARNING: The valve must be checked for seat leak-

age after the set pressure has been checked. Excessive

leakage could lead to fouled or inoperable valves, serious

product loss and could be hazardous to personnel and

equipment.

1. The valve can be tested for tightness on the test stand

by increasing vessel pressure to the required test pres-

sure and observing the valve outlet for evidence of

leakage. The following is an overview of the test proce-

dures used.

Metal SeatedValves:

Metal seated valves shall be tested at 90% of set pressure

when the set pressure is greater than 50 psig; they shall

be tested at 5 psig below set pressure when the set pres-

sure is less than or equal to 50 psig.

AIR - A 5/16 O.D. x 0.035 wall thickness copper tube or

equivalent immersed no more than 1/2 deep in water shall

be connected to the valve outlet. See Figure 6.1. Seal all

other potential leakage paths with suitable fixtures (i.e.,

cap, plugs) so that seat leakage can be detected at the

outlet. Before starting the bubble count, test pressure shall

be applied for a minimum of 1 minute. The valve shall then

be observed for leakage for at least 1 minute. The leakage

rate shall not exceed 40 bubbles per minute.

STEAM - Test pressure shall be applied for 3 minutes

before the seat tightness test. The valve shall be observed

for leakage for at least 1 minute. There shall be no visible

or audible leakage at the valve outlet.

▲

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Appendix A: Critical Seat Dimensions

Unless otherwise specified, all dimensions are ± .005. All dimensions are in inches.

Tolerance 1+.000 2+.003 3+.005 4 ±.010 5 +.000 6+.010

-.005 -.000 -.000 -.010 -.000

SERIES 1890–GUIDE

SERIES 1890–DISC

SERIES 2850R–O-RING BODY

Farris Engineering

Division of Curtiss-Wright Flow Control Corporation

SERIES SIZE A A1 B C C1 D E F G H J K L

2850 3/4 X 1 .7501.7852.8103.1254.1254.0151.284 .700 .894 .459 – – –

& 1 X 1 1/2 1.00011.03721.0603.1254.1254.0151.331 .950 1.125 .611 – – –

2850R 1 1/2 X 2 1.50051.53921.5606.1254.3754.0151.456 1.44021.630 .677 – – –

1890 & 1/2 X 1 .5001– .5603.0624– .0151.076 .450 – .390 .590 .748 .685

1890R 3/4 X 1 .5001– .5603.0624– .0151.076 .450 – .390 .590 .748 .685

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10195 Brecksville Road, Brecksville, OH 44141 USA Telephone: (440) 838-7690 Fax (440) 838-7699 www.cwfc.com

Plant Plants in Canada

Farris Engineering, Brecksville, Ohio USA Farris Engineering, Brantford, Ontario

While this information is presented in good faith and believed to be accurate, Farris Engineering does not guarantee satisfactory results from reliance upon such

information. Nothing contained herein is to be construed as a warranty or guarantee, expressed or implied, regarding the performance, merchantability, fitness or any

other matter with respect to the products, nor as a recommendation to use any product or process in conflict with any patent. Farris Engineering reserves the right,