Caring for your Valves - A guide to getting the most out of your valves- Written by the Valve Pipeline Staff
Valves should be handled, stored and installed with a sense of care. Although they may be capable of severe service and high corrosion proper valve care can help to ensure valves work and last in service.
VALVE CARE - Prior to Installation
· Keep valves in crates/boxes or in a warehouse prior to installation · Do not remove end plugs/flange protectors until installation · Remove disc protector from swing check valves · Close valve before installation · Inspect the inside of the valve and remove any foreign materials · Inspect stem to ensure it is free of dirt, sand or grit · Tighten/check packing nuts prior to installation · Check piping and remove all foreign material
LOCATION - Where the valve is installed
· Valves should be installed in line where they are easy/safe to reach · Valves should be installed in a location that allows the valve to operate properly. · Piping near the valve should be supported adequately to accommodate the additional weight of the valve to the line · Valves with a rising stem should be installed to allow sufficient clearance for operation
INSTALLING - Putting the valve in line
· Threaded valves should be installed using the appropriate sized wrenches with flat jaws. Pipe threads have a standard tolerance. · Flanged valves should be torque up opposite to each other - bolt number 1 should be torque again prior to the last bolt. (i.e. imagine a clock with 12 being up, 6 down, 9 left and 3 right - valves should be tightened in this sequence " 12, 6, 9, 3, 11, 5, 7, 12, 1". · Socket weld valves should be kept CLOSED during welding and post-weld heat treatments (PWHT). PWHT should be done in accordance with accepted standards · Butt weld valves should be installed with extreme care to ensure seats are not distorted during welding
OPERATING THE VALVE
· Prior to putting a valve into service the piping system must be purged and drained · The valve disc/ball/seats can be damaged due to foreign materials trapped in the valve; a drain-trap/other arrangement is advices to collect foreign materials before they can enter/damage a valve
MAINTENANCE - Taking care of the valve
· Valves should have the following inspected on a regular schedule o Stem threads o Packing gland bolting o Flange bolting and gasket o Body-bonnet joint o Grease injectors (if applicable)
· If a valve leaks at the stuffing box; tighten the gland bolting until the leak stops up to a quarter turn. If the leak continues get the valve repaired · If leakage occurs at the body/bonnet joint torque the bolting equally.
· Repairs must be made by a trained professional · Repair operations must be performed with the valve removed from service · Repair space shall be well lit, clean and dry · Repaired valves must be hydro-tested in accordance with API 598
This article is intended to be used as a guide for valve care, when handling valves it is always important to ensure trained professionals are available and consulted to ensure safety and valve care.
Contact - The Valve Pipeline
Gate valves by design typically handle high temperature and are full opening.