Among our many services are included virtually all valve modifications done today. This
section is intended to cover some of the most commonly required. Should some special
service be needed our procedures can be furnished in detail upon request.
Often valves are needed with special trims on the rings, and/or the gate, globe or
clapper. This process involves the removal of any of the original trim material and
deposition of the desired material on the appropriate valve part. Many trim changes, but
not all, involve the manufacture of a new alloy stem for a gate or globe valve. The
desired trim material is usually applied by are-welding and is covered by the ASME Boiler
and Pressure Vessel Code Section IX. The part is then machined to the original shape and
refit to assure a tight seal. Trim changes routinely done include the conversion from
standard trim to 'Stellite', stainless, brass, or monel trim.
- Tap, Drain and Bypass Installation
Taps, drains and bypasses can be installed according to customer requirements and
according to MSS SP-34 and MSS-SP-45 specifications.
- Actuator Conversion Or Installation
Customers' valves can be converted to accept any type of actuator or operator be it
manual, electric, hydraulic or pneumatic to customer and/or actuator manufacturer
specification. Our modification facility is also capable of furnishing valves with
actuators installed. All customer and/or manufacturers requirements will be specified.
- Bonnet Extensions for Crvoaenic Service
Successful operation of a valve at temperatures as low as minus 425"F requires
special design considerations. Due to the high shrinkage of plastic packing materials with
decrease in temperature the packing must be kept a sufficient distance away from the cold
line fluid to remain functional. This is accomplished with an extended bonnet of
sufficient length to provide an insulating gas column. The design for each manufacturer of
valve will vary depending on the design of the valve before modification. A longer
extension can be provided to customer specification.
As with the valves we repair, all modified valves are tested and inspected before being
shipped. The same specifications that apply for repaired valves are used when testing