 |
|||
|
|
|||
| ||||||||||
|
|  MIL-V-24642(SH)
3.3.1 Hard facing of seats and discs. The seating surfaces of discs and
seats shall be hard faced. Welding rods used for hard facing shall be type
MIL-RCoCr-A of MIL-R-17131. The finished thickness of hard faced surfaces
shall be not less than 3/32 inch. Seating surface shall be liquid penetrant
inspected after final machining in accordance with MIL-STD-278 (see 3.4.11.7.2).
3.3.2 Handwheels. Handwheels 10 inches and smaller in diameter shall
be of malleable iron or aluminum. Handwheels larger than 10 inches in diameter
shall be of aluminum alloy.
3.3.3 Recovered materials. Unless otherwise specified herein, all
equipment, materials, and articles incorporated in the products covered by
this specification shall be new and shall be fabricated using materials
produced from recovered materials to the maximum extent practicable without
jeopardizing the intended use. The term "recovered materials" means materials
which have been collected or recovered from solid waste and reprocessed to
become a source of raw materials, as opposed to virgin raw materials. None of
the above shall be interpreted to mean that the use of used or rebuilt products
is allowed under this specification unless otherwise specifically specified.
3.4 Design and construction.
3.4.1 Threads. Where necessary, provisions shall be incorporated to
prevent the accidental loosening of threaded parts. Pipe threads shall not
be used. The threads on all threaded fasteners, except handwheel nuts, shall
be coated with antiseize compound in accordance with MIL-A-907 prior to
assembly.
3.4.2 Interchangeability. Valve design shall permit interchangeability
without individual modification of like parts between valves. Each part shall
have part number identity, and shall be replaceable on a nonselective and
random basis. Physical interchangeability shall be in accordance with the
following definition: Interchangeable assemblies, components, and parts are
those which are capable of being readily installed, removed, or replaced
without alteration, misalinement, or damage to parts being installed or to
adjoining parts. No fabrication operations such as cutting, filing, drilling,
reaming, hammering, bending, prying, or forcing shall be required. This does
not preclude lapping in metal-to-metal seating surfaces to obtain required seat
tightness. No special tools shall be required for maintenance of the valve.
Parts having the same manufacturer's part number shall be directly interchange-
able with each other with respect to installation and performance without
requiring selection or fitting.
3.4.3 Accessibility. Valves shall be accessible for adjustment, repair,
or replacement of the solenoid without requiring removal from the line.
3.4.4 Maintainability. Valve design shall permit disassembly and
reassembly of internal parts with standard tools and prevent the incorrect
reassembly of parts. Positioning and alinement of all parts in the assembly
shall employ a positive means so that correct reassembly is repeatedly assured.
3.4.5 Cyclic life. Valves shall pass the cyclic life test of 2,000
cycles as specified in 4.6.4. During and subsequent to this test, valves
shall not fail to perform their principal function as specified in 3.2.
5
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals