Flowserve Cast Globe Valves - Manual (Page 14)

Globe Valves FCD ADENIM0011-00
14
5.0 VALVE MAINTENANCE
Anchor/Darling Valves are designed to be essentially maintenance free pieces of equipment. When-used in the proper
application and operated correctly, they will provide reliable operation for many years. The only area that is expected to
require regular attention is the adjustment and (if necessary) replacement of the stem packing. The frequency of this
operation will be dependent on the service conditions, the type of packing used and the care with which it is installed. Some
other maintenance recommendations are included in the following sections for information.
5.1 Inspection
The most important aspect of valve maintenance is periodic inspection. The early detection of a malfunction can, in
many cases, prevent a minor defect from becoming a major problem. It is very important that leakage from any of the
major seals (packing, disc/seat, body-bonnet) be addressed immediately. The smallest weepage can quickly
become a major problem if it is not treated promptly. Some other areas that should be included in a periodic
inspection program are:
1. Lubrication: - Stem
- Yoke Sleeve
- Motor Actuator Drive Sleeve
- Pneumatic Actuator Sliding Surfaces
2. Cleaning: - Stem
- Packing Area
- Pressure Seal Area
- Body Bonnet Studs
3. Bolting: - Body-Bonnet
- Bonnet Yoke
- Motor Actuator
4. Packing Adjustment
5.2 Lubrication
1. Stem: Keep stem threads lubricated with a light coating of grease (NLG1 No.2 or equal).
2. Yoke Sleeve: Lubricate with general purpose grease every six-months. Apply with grease gun to grease-fitting
(Item 340).
3. Air cylinder operated-valves require only a light coating of grease or oil on the stanchions.
4. Motor Actuator: Every six months lubricate drive sleeve top bearing, using grease gun on pressure fitting in
housing cover. See Motor Actuator Manual for further information.
5.3 Cleaning
The frequency and extent of cleaning will depend on the valves' location and service conditions. It is important
that the stem and packing gland parts be kept clean and free of foreign material. Do not allow water or dirt to
collect in the body neck bore area above the pressure seal of pressure seal valves. The build-Up of corrosion or
extraneous material may interfere with removal of the bonnet. For the same reason excessive rust should not
be allowed to build-up QD the body-bonnet bolting of bolted bonnet valves.