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|  MIL-V-17501F(SH)
3.6.11 Manual operating mechanism. The operating mechanism for type II valves shall consist
of a handle and a spring-loaded lever containing a position indexing pin. The valve cover shall
have indexing holes that shall permit the valve to remain in one of the designated positions. Type
II valves operating mechanism shall be constructed for through bulkhead operation, thereby
permitting valve operation from an adjacent compartment. A locking device with provisions for
wiring the device in place shall be provided. Type I, class 1 valves shall incorporate a manual
operating mechanism for emergency valve operation. The type I, class 1 manual operating
mechanism shall operate smoothly and rapidly and shall not interfere with the valve's flow or
normal hydraulic actuation.
3.6.12 Dial plate. Type II valves shall have a dial plate permanently attached to the valve
cover. The dial plate shall contain capitalized valve position nomenclature in accordance with
figure 1. The dial plate may also contain valve identification information as specified in 3.11.3.
3.6.13 Test fittings. Unless otherwise specified (see 6.2), removable test fittings shall be
constructed to be screwed onto the bottom portion of type I, class 1 valve bodies in place of the
bottom cap. The test fitting shall be a one-piece casting that incorporates a threaded bottom cover
and a male threaded extension for accommodating a firehose coupling. The male threaded
extension shall conform to national flrehose threads. For type I, class 1 valve sizes 1 to 3 inches,
the extension thread size shall be 1- 1/2 inches, 11 threads per inch (TPI), and for valve sizes 3- 1/2
to 12 inches the thread size shall be 2-1/2 inches, 7-1/2 TPL
3.6.14 Removable parts. Temporarily removable valve parts such as bottom caps and locking
devices shall have a permanent means, such as a chain or braided wire, for connecting the remov-
able part to the valve body. This requirement shall not include removable test fittings.
3.6.15 Alignment. Components and assemblies that are alignment-critical shall be positively
held in place by dowel pins, fitted bolts, keys, rabbeted or tongue and groove joints, or other
indexing means, as appropriate. The construction shall ensure that the alignment is not disturbed
or any undue stresses are induced in service as a result of the alignment means. Where the bonnet,
dome or cover and body or distributor incorporate valve stem guides, the bonnet, dome or cover
and body or distributor mating flanges shall be provided with a positive means to facilitate and
maintain perfect alignment of the valve stem guides to ensure free movement at any angle of valve
installation in service.
3.6.16 Installation orientation. Although type I valves are normally installed with the valve
body horizontal, they shall be suitable for free and smooth operation m any position. Type II
valves shall be constructed for through bulkhead type installation with the stem in the horizontal
position.
3.7 Shipboard environmental conditions. Valves shall be constructed to perform their
required functions in a reliable manner when installed and operated on board Navy ships under
the specified shipboard environmental conditions, w h i c h shall be understood to prevail
simultaneously and to occur in any combination.
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