Instruction manual

ManualsBrandsEmerson Manualsmotor vehicle accessories & componentsA31A

Instruction Manual

D500240X012

A31A Valve

October 2012

6. Attach the bonding strap assembly (key 131, figure 6) to the shaft with the clamp (key 130, figure 6).

7. Connect the other end of the bonding strap assembly to the valve flange cap screws.

8. For more information, refer to the Packing Maintenance section below.

Installing Single-Flange Valves

WARNING

The edges of a rotating valve disk have a shearing effect that may result in personal injury. To avoid personal injury, keep

clear of the disk edges when rotating the disk.

1. Seefigure5forrecommendedvalveorientation.See table 5 for hex head cap screw specifications.

2. Properly orient the valve according t o the specific application. For optimum performance, install the valve for

reverse flow.

3. Position the v alve between the flanges.Besuretoleaveenoughroomfortheflange gaskets. Install the lower flange

bolts.

4. Select the appropriate gaskets for the application. Flat sheet, spiral wound, or other gasket types, made to the

ASME B16.5 group standard or user's standard, can be used on the valve depending on the service conditions of the

application. Install the gaskets and align the valve and the gaskets.

5. Install the remaining bolts.

6. Tighten the flange bolts in an alternating criss-cross fashion to a torque value of one-fourth of the final bolting

torque. Repeat this procedure several times increasing the torque value each time by a fourth of the final desired

torque. When you get to the final torque value, tighten each flange bolt again to allow for gasket compression.

Table 6. Torque Values for Fasteners

FASTENER NOMINAL SIZE

Retaining

Ring

Screws

#10 1/4 5/16 3/8 7/16 1/2 9/16 5/8 3/4 7/8 1 1-1/8

LbfSin LbfSft

41 100 220 400 53 83 119 166 296 480 720 1000

NSm

4.6 11 25 45 72 112 161 225 401 651 976 1356

Gasket

Retaining

Bolts

LbfSin LbfSft

35 81 167 295 39 59 86 119 210 330 480 617

NSm

4.0 9.2 19 33 53 80 117 161 286 447 651 837

Note: These values are based upon standard materials, S66286/N07718 screws and ASTM A193GRB6 bo lts. For other special fastener materials, please contact your Emerson Process Manage

ment sales office.

Maintenance

WARNING

Avoid personal injury from sudden release of process pressure. Before performing any maintenance operations:

D Do not remove the actuator from the valve while the valve is still pressurized.

D Disconnect any operating lines providing air pressure, electric power, or a c ontrol signal to the actuator. Be sure the

actuator cannot suddenly open or close the valve.