Water Hammer

DOE-HDBK-1132-99

normally sized to not exceed the flow capacity of the downstream drip

legs to handle the condensate collection during the initial startup of the

steam system.

Steam header control valves and pressure regulators should be provided

with upstream stainers. Pressure regulators should have upstream drip

legs and manual bypass lines.

Stream traps should provide adequate capacity to accommodate

condensation loads during warm-up as well as during normal operation

and to compensate for line size, length, and insulation type and

thickness. Traps for end user equipment (e.g., heating coils) normally

accommodate full condensate load from the equipment warm-up in order

to be considered automatic draining.

Arimid fiber gasket material should not be used in any steam or

condensate service.

Water Hammer.

3.1.5

Various devices can be used to protect piping systems from damage

caused by severe hydraulic transients. Check valves, standpipes, and

accumulators can prevent the occurrence or reduce the effect of a

transient event.

Vacuum-breaker valves should be used in situations where water-column

separation can occur. Check valves (preferably titling disc) can also be

used to prevent column separation in the event of power loss.

3.2

Purge Systems. Chemical processing vessels in nonreactor facilities often handle

materials that are both flammable and potentially explosive. An effective way of

controlling the potential for fire and explosions in these vessels is either to control the

fuel in the tank by diluting and sweeping the vapor space with purge gas or to limit the

oxygen content in the vapor space by blanketing with an inert gas. The type of purge

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