Römheld GmbH
· Postfach 12 53 · D-35317 Laubach · Phone + 49 (0) 64 05 / 89-0 · Fax +49 (0) 64 05 / 89-211 · www.roemheld.com
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Fitters and setters of machine tools. They
have to be familiar with the handling and
mounting of hydraulic components.
Locking of leakage-free hydraulic
cylinders, i. e. for maintaining the
pressure and/or the position, can also be
used in combination with non-leakage
free directional control valves.
Pilot-operated check valves are not
suitable for locking of double-acting swing
clamps (pull-type cylinders). Due to the
unfavourable surface ratio of these
elements, the control pressure is not
sufficient for unlocking and dangerous
pressure intensifications occur. For such
applications use type 2951-421.
!
Swarf or contamination in the hydraulic
oil lead to increased wear or damage at
the guides, running surfaces and seals.
!
The maximum operating pressure and
the admissible flow rate of the valve
must not be exceeded.
!
Use hydraulic oil as per Roemheld data
sheet A 0.100.
Check valves are spring-loaded ball-type
poppet valves (leakage free).
The flow B
→
A is free. The flow from A
→
B is locked, but it can be hydraulically
unlocked by pressurising control port Z.
Operating Instructions
Check Valves, Pilot Operated
These operating instructions are
available for pilot-operated check
valves of the following types:
2951-416
2951-417
2951-421
2951-501
Target group of this
document
Provided use
Safety
Troubles of functioning
Protect against swarf, otherwise
check valves might not seal.
Instructions for safe
operation
Function
B
A_D8755
Issue 03/2004