RE 18318-55/08.2022, Bosch Rexroth Oil Control S.p.A.
Pressure reducing and relieving,
direct acting spool type
Special cavity, R/LA
RE 18318-55
Edition: 08.2022
Replaces: 02.2021MHDRDB
Technical data
General
Weight 0.17kg (0.37lbs)
Installation position Any
Ambient temperature range -20 to 80°C (-4 to 176°F)
Hydraulic
Max. operating pressure
port 2
420bar (6090psi)
Max. control pressure
port 1
35, 40 bar (508, 580 psi)
Max. tank pressure
port 3
30 bar (435 psi)
Max. flow 15 l/min. (4 gpm)
Fluid temperature range -20 to 100°C (-4 to 212°F) for FKM
Fluids: Mineral-based or synthetics with lubricating properties at
viscosities of 10 to 800 mm
2
/s (cSt)
Installation torque 54 - 66 (40 - 49 ft-lbs)
Filtration Class 20/18/15 ISO 4406
Special cavity R/LA see page RE 18325-75
Load cycles 2 million
Note: The valves are not provided with any surface protection.
Description
Initially, flow passes freely from 2 to 1. When the pressure
at 1 exceeds the pressure setting, the valve acts to restrict
input flow at 2. This increases the pressure drop through
the valve and maintains consistent pressure at 1. The spring
chamber is drained at 3 to prevent a build-up of back-pressure
against the spool. Additionally, if pressure at 1 rises above
the pressure setting, flow is relieved to 3 until the setting
is re-attained. An undesirable increase in pressure in main
port 1 is additionaly prevented by lifting the spring plate off
the control spool. Tank pressure is additional to the spring
setting.
T, Y
A
P
Bosch Rexroth Oil Control S.p.A., RE 18318-55/08.2022
2 MHDRDB | Pressure reducing and relieving direct acting spool type
Ordering code
MHDRDB 04 K 0 - 1X/ LA *
Pressure reducing and relieving
direct acting spool type Further details in clear text
V =
Seal material
FKM seals
(other seals on request)
Attention!
Observe compatibility of seals
with hydraulic fluid used!
Component series 10 to 19
(10 to 19: unchanged installation and connection dimensions)
35 bar 035
40 bar 040
(lower pressure ratings on request)
Preferred types
Type Material number
MHDRDB-04-K0-11/035VLA R900641606
MHDRDB 04 K0-11/040VLA R900751628
Type Material number
RE 18318-55/08.2022, Bosch Rexroth Oil Control S.p.A.
Pressure reducing and relieving direct acting spool type | MHDRDB 08.2022 3
Characteristic curves
4
Bosch Rexroth Oil Control S.p.A., RE 18318-55/08.2022
Bosch Rexroth Oil Control S.p.A.
Via Leonardo da Vinci 5
P.O. Box no. 5
41015 Nonantola – Modena, Italy
Tel. +39 059 887 611
Fax +39 059 547 848
compact-hydraulics-cv@boschrexroth.com
www.boschrexroth.com/compacthydraulics
© This document, as well as the data, specifications and other information set
forth in it, are the exclusive property of Bosch Rexroth Oil Control S.p.a.. It
may not be reproduced or given to third parties without its consent. The data
specified above only serve to describe the product. No statements concerning
a certain condition or suitability for a certain application can be derived from
our information. The information given does not release the user from the
obligation of own judgment and verification. It must be remembered that our
products are subject to a natural process of wear and aging. Subject to change.
MHDRDB | Pressure reducing and relieving direct acting spool type
Dimensions [mm (inches)]
Dimensions
▼ Pressure reducing and relieving direct acting spool type
