Page 66 - Paker - Medium Duty Hydraulic Cylinders

Catalog HY08-1130-4/NA Medium Duty Hydraulic Cylinders
Common Modifications Series 3L Custom Modifications

Modifications: The following modifications can be of a collapsing cover should be considered. This is
supplied on most Parker cylinders. commonly referred to as a “boot”. Calculate the longer
rod end required to accommodate the collapsed length
Metallic Rod Wiper of the boot from the following data.
When specified metallic rod wipers can be supplied
instead of the standard synthetic rubber wiperseal. LF .13 .13 .13 .13 .13 .13 .13 .10 .10 .10 .10 .10
Recommended in applications where contaminants tend OD 2.25 2.25 2.63 3.00 3.38 3.75 4.38 5.13 5.63 6.25 7.00 7.50
to cling to the extended piston rod and would damage MM .500 .625 1.000 1.380 1.750 2.000 2.500 3.000 3.500 4.000 5.000 5.500
the synthetic rubber wiperseal. Installation of metallic rod .50 .63
wiper does not affect cylinder dimensions. It is available To determine extra length
at extra cost. of piston rod required to
accommodate boot, calculate
Gland Drain BL = Stroke x LF + 1.125"
Hydraulic fluids tend to adhere to the piston rods, during BL + Std. W + A = length of
piston rod to extend beyond the
the extend stroke, and an accumulation of fluid can retainer. MM OD
collect in the cavity behind the gland wiperseal on long NOTE: Check all Boot O.D’s
stroke cylinders. against std. “E” dimension from
catalog. This may be critical on
A 1/8" NPTF gland drain port can be provided in the foot mounted cylinders.
gland retainer. A passage in the gland between the BL
wiperseal and lipseal is provided to drain off any accu- Tandem Cylinders
mulation of fluid between the seals. See drawing below. A tandem cylinder is made up of two cylinders mounted
It is recommended that the gland drain port be piped in line with pistons connected by a common piston rod
back to the fluid reservoir and that the reservoir be and rod seals installed between the cylinders to permit
located below the level of the head of the cylinder. double acting operation of each. Tandem cylinders allow
increased output force when mounting width or height
are restricted.

ØMM

Reduced operating pressure is required for this construction. Please
contact the factory.

Air Bleeds Duplex Cylinders
In most hydraulic circuits, cylinders are considered A duplex cylinder is made up of two cylinders mounted
self-bleeding when cycled full stroke. If air bleeds are in line with pistons not connected and with rod seals
required and specified, 1/8" NPTF Air Bleed Ports for installed between the cylinders to permit double acting
venting air can be provided at both ends of the cylinder operation of each. Cylinders may be mounted with
body, or on the head or cap. To order, specify “Bleed piston rod to piston (as shown) or back to back and are
Port”, and indicate position desired. generally used to provide three position operation.

Air Bleed Port
ØMM

ØMM ØMM
Rod End Boots
Cylinders have a hardened bearing surface on the
piston rod to resist external damage, and are equipped Reduced operating pressure is required for this construction. Please
contact the factory.
with the high efficiency “Wiperseal” to remove external
dust and dirt. Exposed piston rods that are subjected
to contaminants with air hardening properties, such as
paint, should be protected. In such applications, the use

56 Parker Hannifin Corporation
Industrial Cylinder Division
www.parker.com/cylinder Des Plaines, Illinois