Flowserve V-376 R4 Edward Valves Manual de usuario descargar pdf (Pagina 9)

10

Flow Control Division

Edward Valves

Valves of the screwed bonnet/cover type

construction are sealed at the bonnet by

flat, soft metal gaskets and “O”- Rings.

Screwed-in seats are also sealed by “O”-

Rings. Such seals require smooth clean

surfaces on body, bonnet or seat. Bolted

bonnet valves, such as Fig. 848 type, are

sealed with spiral-wound gaskets. In all

valves, new gaskets (and “O”- Rings) are

recommended for reassembly. Bonnet gas-

kets (and “O”- Rings) are inexpensive and

available out of factory stock.

Valves with screwed bonnet/cover joints

require the bonnet threads to be well lubri-

cated and tightened to develop sufficient

gasket compression.

Bolted Bonnet/Cover Torques

A torque wrench should be used for tight-

ening the bonnet, which is used to preload

the spiral-wound gaskets.

The following procedure is recommended:

1. Guard against leakage by having these

capscrews tight at all times.

2. Capscrews should be tightened to the

torque shown below.

Step #1

Snug to approximately 10% of full recom-

mended torque. Sequence:1-2-3

Step #2

Torque to approximately 75% of full recom-

mended torque. Sequence:4-3-2

Step #3

Torque to full recommended torque.

Sequence: 1-2-3-4

Note: The above noted method for tighten-

ing cover capscrews is for the purpose of

pulling the cover down evenly. If this objec-

tive can be achieved without following this

suggested method precisely, then some

variation from this method is permissible.

Welding Edward Valves into Piping

Welding is outside the scope of this manu-

al, but Edward recommends you consult

the appropriate welding procedure in

ASME/ANSI B31, or whatever other codes

apply to your system. When welding

Edward valves into piping, make sure

there is no foreign material on the seat

joint, then close the valve tightly to avoid

distorting the seats.

After welding, open the valve and flush the

line to clean out all foreign matter.

Lubrication

In order to obtain full service life, valves

require periodic lubrication of the stem

threads. Exposed threads should be wiped

clean of old grease and accumulated dirt

and fresh lubricant applied. This is most

effectively done with the valve in the

closed position.

For valves that see frequent operation,

such as motor-actuated, the lubricant

should be replenished every three months.

If extreme service conditions dictate, a

more frequent relube schedule is recom-

mended. Motor-actuated valves have a

lubricant fitting at the yoke flange.

The recommended lubricant for all stem

threads, bonnet, packing nut and bolt

threads is Rykon EP #2, manufactured by

the American Oil Company. This is an

extreme pressure, extreme temperature

lubricant of high quality. For valves that

are operated infrequently, relubrication

should be at least once a year.

Reassembly

SEAT BONNET/

VALVE FIGURE RING COVER

SIZE NUMBER TORQUE TORQUE

1/4, 3/8, 1/2 158,160 75 40

3/4 158,160 100-120 60

1 158,160 240-260 125

1-1/4, 1-1/2 158,160 320-340 150

2 158,160, 400-420 300

5158, 5160

9160

Seat Ring & Bonnet/Cover Torques

NOTE: TORQUE IS MEASURED IN FOOT-POUNDS

Bolt diameter, Inches

3/8 7/16 1/2 9/16 5/8 3/4 7/8 1 1-1/8 1-1/4

Torque, Ft. Lbs.

18 30 45 68 90 150 240 370 585 750

1 2 3 4 5 6 7 8 9 10 11

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