costs of the project.
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The piston rod shall be made of [carbon steel with nickel and chrome
plating] [,] [or] [stainless steel with chrome plating] [,] [or] [carbon
steel with ceramic coating]. If the piston rod is composed of two or more
pieces, the welds shall be radiographed. [For the carbon steel piston rod
with nickel and chrome plating, the rod shall be fabricated from carbon
steel conforming to ASTM A 108, Type C 1045, or ASTM A 331, Type CR 4140.
It shall be case hardened to 50-54 Rockwell C, polished to a 0.25 micrometer
10 microinchRMS surface finish or better, and nickel and hard-chrome
plated to 75 micrometer 0.003 inch minimum thickness. The final chrome
plated surface shall have a roughness height of not more than 0.20
micrometer8 microinch RMS.] [For the carbon steel piston rod with ceramic
coating, the steel shall conform to ASTM A 108, Type C 1045, or ASTM A 331,
Type CR 4140. The ceramic coating shall have a 200 micrometer 0.008 inch
minimum thickness, surface finish of0.30 micrometer 12 microinches RMS or
better, surface hardness of 67 Rockwell C minimum, impact resistance of 7
to 15 N-m 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.] [For the stainless steel
piston rod with chrome plating, the stainless steel shall conform to ASTM A
564/A 564M or ASTM A 705/A 705M, Type 630 or Type XM-12. It shall be heat
treated to a condition of H-1150 before final machining. The final rod
surface after chrome plating shall have a roughness height of not more than
0.20 micrometer 8 microinch RMS.]
2.1.5.2
The piston shall be cast iron conforming to ASTM A 536, Grade 80-55-06 or
10-50-05.
2.1.5.3
Piston Wear Rings
Piston wear rings shall be glass-reinforced nylon with a compressive and
tensile strength of not less than 165 MPa 24,000 psi and an embedability
capability to prevent scoring of the cylinder.
2.1.5.4
O-Ring Seals
The O-ring seals shall be [Buna N] [Viton] and designed for [_____] kPa psi
service.
2.1.5.5
Rod Wiper
The rod wiper shall be a high-strength polyurethane scraper ring which will
withstand the impact and the abrasion of materials adhering to the piston
rod.
2.1.5.6
[Piston and] Piston Rod Seals
[Piston and] piston rod seals shall be of the low leakage V-ring,
nonadjustable gland type, designed for [_____] kPa psi service. [Piston
seals shall be bronze-filled polytetrafluoroethylene.]
SECTION 15010A
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