Flowserve Vogt Forged Steel Gate - Manual (Page 24)

Flow Control
Vogt Valves
24 Forged Steel Gate, Globe and Check Valves FCD VVENIM2000-02
4.11 Testing and Adjustment
It is reasonable to assume that a valve that has been properly
inspected and installed will be in good condition and ready to
operate. However, the actual operability of a valve can only be
proved by testing.
A first observation can be made by actuating the valve through an
open-close-open or close-open-close cycle. If no obvious problems
are observed, an actual test at pressure may then be applied while
tightness and operability are checked.
It is common practice, after the installation of a piping system,
to clean the system by blowing through the system with a gas or
steam or flushing with a liquid to remove debris and/or internal
protective films and coatings. It should be recognized that valve
cavities may form a natural trap in a piping system and material not
dissolved or carried out by the flushing fluid may settle in such cavi-
ties and adversely affect valve operation.