Design CP/ENVIRO-SEALR Bellows Seal Table 3. Recommended Torque for Packing Flange Nuts (1) VALVE SIZE, INCHES
VALVE STEM DIAMETER Inch
1 1-1/2, 1, 1 1/2 2 3 4 3,
1/2 3/4
GRAPHITE TYPE PACKING Minimum Torque
Maximum Torque
Minimum Torque
Maximum Torque
LbfSin
NSm
LbfSin
NSm
LbfSin
NSm
LbfSin
NSm
150
32
3.6
48
5.4
15
1.7
23
2.6
300
43
4.8
64
7.2
20
2.3
31
3.5
150
66
7.5
99
11.2
31
3.5
47
5.3
300
88
10.0
132
15.0
42
4.8
63
7.2
mm 12 7 12.7 19 1 19.1
PTFE TYPE PACKING
ANSI CLASS
1. Torques are for standard packing only. Refer to the appropriate instruction manual for packing nut tightening requirements for ENVIRO-SEAL packing.
Valves with ENVIRO-SEAL packing will not require this initial re-adjustment. See your Fisher Controls instruction manual titled ENVIRO-SEAL Packing System for Sliding-Stem Valves for packing instructions. If you wish to convert your present packing arrangement to ENVIRO-SEAL packing, refer to the retrofit kits listed in the parts kit subsection near the end of this manual.
Maintenance WARNING Avoid personal injury or property damage from sudden release of process pressure or bursting of parts. Before performing any maintenance operations: D Disconnect any operating lines providing air pressure, electric power, or a control signal to the actuator. Be sure the actuator cannot suddenly open or close the valve. D Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure from both sides of the valve. Drain the process media from both sides of the valve. D Vent the power actuator loading pressure and relieve any actuator spring precompression. D Use lock-out procedures to be sure that the above measures stay in effect while you work on the equipment. Due to the care Fisher Controls takes in meeting all manufacturing requirements (heat treating, dimensional tolerances, etc.), use only replacement parts manufactured or furnished by Fisher Controls.
4
Valve parts are subject to normal wear and must be inspected and replaced as necessary. Inspection and maintenance frequency depends on the severity of service conditions. This section includes instructions for packing lubrication, packing maintenance, and trim maintenance. All these maintenance operations may be performed with the valve in the line. Note Whenever a gasket seal is disturbed by removing or shifting gasketed parts, a new gasket should be installed upon reassembly. This is necessary to ensure a good gasket seal, because the used gasket will not seal properly. Note If the valve has ENVIRO-SEAL packing installed, refer to instruction manual titled ENVIRO-SEAL Packing System for Sliding-Stem Valves, Form 5306, for packing instructions. Figure 3 in this manual shows typical ENVIRO-SEAL packing systems.
Packing Maintenance WARNING On a valve equipped with an ENVIRO-SEAL bellows seal bonnet, packing leakage may be an indication of a broken or failed bellows seal, which could result in personal injury. On a valve equipped with an ENVIRO-SEAL bellows seal bonnet, packing is a secondary seal in case the bellows seal fails. Packing leakage may be an indication of a broken or failed bellows seal. First, tighten the packing per instructions in the Tightening Packing section. Then, if leaking persists, check the ENVIRO-SEAL bellows seal for failure.