Figure 1-14. Vacuum leak test cycle.
(4) Phase 13: pressure pulse (first). Steam pressurizes the chamber
through 1SOL. 5SOL is energized (opened) permitting cooling water to condense
steam from the chamber and drain to waste. When the chamber pressure reaches (F)
44psia, 1SOL and5 SOL are de-energized (closed) and Phase 12, negative pulse,
begins.
(5) Phase 12: negative pulse (first). 2SOL and 6SOL are energized
(opened). Chamber steam is exhausted to the ejector, condensed, and drained. When
the chamber pressure is reduced to 9.7psia, 2SOL and 6SOL are de-energized
(closed).
(6) Phase 13: pressure pulse (second). Steam pressurizes the chamber
through 1SOL. 1SOL and 5SOL are energized (opened). When the chamber pressure
reaches (F) 44psia, 1SOL and 5SOL are de-energized (closed), and the second Phase
12, negative pulse, begins.
(7) Phase 12: negative pulse (second). This phase is identical to first Phase
12, negative pulse, except the chamber pressure is reduced to 4.8psia before 2SOL
and 6SOL are de-energized (closed), and the third Phase 12, negative pulse, begins.
(8) Phase 13: pressure pulse (third). This phase is identical to second
Phase 12, negative pulse.
MD0354
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