PART 5 Flashcards
Any short piece of pipe, especially if threaded at both ends with male threads.
nipple
Inspection tests that are not destructive to the valve structure or function.
nondestructive examination (NDE)
A gate valve having its stem threaded into the gate.
nonrising stem
The deformable sealing material inserted into a valve stem stuffing box, which provides a tight seal about the stem when compressed by a gland.
packing
A temporary drilling site, usually constructed of local materials such as gravel, shell or even wood.
pad
A fluid used to initiate hydraulic fracturing that does not contain proppant.
pad
When daily usage of natural gas is charted on graphs, high peaks of usage during the winter and summer months can be detected
peak shaving
A regulator that is controlled by a second small-volume, high-accuracy regulator or pilot.
pilot-operated regulator
The external input shaft of certain gear operators, which drives the internal reduction gearing.
pinion shaft
The sealing principle involved in utilizing line pressure to effect a seal across the floating seats of some valves.
piston effect
Pertaining to screw threads, the pitch refers to the measurement between adjacent threads
pitch-and-lead
A quarter-turn valve whose closure element is usually a tapered plug having a rectangular port.
plug valve
A Christmas tree that is installed once fracturing has been completed and the frac tree has been removed.
production tree
A nondestructive evaluation (NDE) procedure that uses X-rays for locating flaws in welds, casting and fabricated parts.
radiographic inspection
A quick-acting, spring-loaded valve that opens to relieve pressure when the pressure exceeds the spring setting.
relief valve
