pertinent information concerning the manufacturer's "equal to" standard
products which he intends to incorporate in the work. "Equal to" standard
products installed or used without such approval shall be at the risk of
subsequent rejection.
2.1.3
Hydraulic Cylinders (Standard Design)
**************************************************************************
NOTE: Alternate 1 shall be used when hydraulic
cylinders of standard design and manufacture are
required.
**************************************************************************
The hydraulic cylinder shall be one of the types listed in ISO 5598, and
specified or indicated, of tie rod design, square head standard
construction. The pressure rating of the cylinder shall not be less than
the maximum system pressure indicated. The manufacturer shall produce
evidence that each cylinder was hydrostatically tested to 200 percent of
the severest service rating and that dynamic seals are suitable for both
frequent and infrequent operation and are capable of not less than 500,000
cycles of operation in systems properly maintained. The bore, stroke, rod
diameter, and mounting style of the cylinder shall be as indicated. The
hydraulic cylinder shall have [adjustable] [nonadjustable] cushions on [the
cap end only] [the rod end only] [both ends]. [Cushions shall have free
reverse flow check valves.] The cylinder shall be provided with double end
rods where indicated and the piping ports shall be [SAE straight thread
O-ring] [SAE 4 bolt hydraulic flanges] [_____].
2.1.3.1
Cylinder Tubes
The cylinder tube shall be machined from ASTM A 519, Grade 1018, heavy wall
seamless steel tubing and shall have the bore honed to a surface finish
compatible with the seals being used so as to result in zero leakage past
the seals.
2.1.3.2
Cylinder Heads and Caps
The cylinder head and cap shall be fabricated from [ASTM A 576, Grade 1018,
steel bar stock] [ASTM A 516/A 516M, Grade 60 plate] and machine finished
on all surfaces. The cylinder head shall be equipped with a rod seal and
external dirt wiper and shall have a rod bushing piloted into the head to
ensure concentricity. [Rod bushings shall be removable without the use of
special tools and without removing the tie rods or cylinder head.]
Attachment of the cylinder tube to the head and cap shall be by tie rods
having a minimum yield strength of 690 MPa. 100,000 psi. Removable
attachments shall have the cylinder tube end seals arranged to seal with
pressure and shall be designed to prevent shearing and extrusion and to
provide axial metal backup.
2.1.3.3
The piston shall be precision fitted to the cylinder body bore. The piston
shall be [fine-grained cast iron] [_____] and shall be designed and
equipped with [zero leakage cup-type seals] [bronze-filled
polytetrafluoroethylene seals with phenolic wear rings]. The design shall
protect the piston rings from blow-out and oversqueezing. [Cup-type seals
shall be self-regulating and shall automatically compensate for wear.]
SECTION 15010A
Page 16
Previous Page
