or better, surface hardness of 67 Rockwell C minimum, impact resistance of
7 to 15 Nm 5 to 11 lb-ft, modulus of elasticity of 360 to 415 GPa 52 x 106
to 60 x 106 psi, linear expansion coefficient of 7.2 x 10-6/degree C 4.0 x
41 ksi minimum. The ceramic coating shall provide a homogeneous,
uninterrupted, non-conducting and impermeable layer capable of providing
corrosion resistance for a minimum of 1000 hours in accordance with ASTM G
85. The use of sealers shall not be permitted.] Rings, bearings, packing,
packing rings, retaining rings, seals, wiper-scrapers, etc., shall be
fabricated from the finest selected quality materials as recommended by the
Contractor to provide zero leakage. Where a cylinder head is used as a
positive-position stop, the stop head shall incorporate an adjustable
cushion, or an external deceleration control shall be provided to minimize
detrimental mechanical impact. [End mounts [for pinned connections] shall
be as shown.] [Bronze bushings conforming to ASTM B 505/B 505M, Alloy
C92900, shall be provided in the pin holes.] [Connection pins shall be
fabricated from ASTM A 564/A 564M, Type 630, Condition H-1150, stainless
steel.] [The hydraulic cylinder shall be mounted as shown.]
2.1.5
Hydraulic Cylinders (Corps Design)
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NOTE: Alternate 3 shall be used when the hydraulic
cylinders have been designed by the Corps of
Engineers and they are detailed on the contract
drawings.
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The outside of the finished cylinder shall be turned concentric with the
bore, and the interior shall be honed to the dimensions, tolerances, and
finish shown. The finished wall thickness shall not be less than that
shown. Flanges shall be welded to the cylinder parallel with each other
and perpendicular to the cylinder center line. Tolerances shall be as
shown. After completion of all welding, the cylinder shall be stress
relief heat treated. [All welds shall be radiographed including those on
the end mounts.] [Designated welds shall be radiographed as indicated.]
The assembled cylinder shall be of such straightness that the piston and
rod move smoothly therein without any indication of binding or tight spots.
Surface finishes shall be as indicated. The cylinder material shall be
steel conforming to one of the following options:
a. Option A: Rolled steel plate conforming to the requirements of
ASTM A 516/A 516M, Grade 70, and welded flanges conforming to ASTM A
181/A 181M, Class 70.
b. Option B: The shell shall be centrifugal cast steel conforming to
the requirements of ASTM A 216/A 216M, Grade WWC, and welded flanges
conforming to ASTM A 181/A 181M, Class 70, or cast from ASTM A 216/A
216M, Grade WWC steel.
c. Option C: The shell and flanges shall be a solid trepanned forging
conforming to the requirements of ASTM A 266/A 266M, Class 1.
2.1.5.1
Piston Rods (Corps Design)
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NOTE: The designer may choose one or more options
depending on the unique requirements and life-cycle
SECTION 15010A
Page 18
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