Ross Controls 2_2 WAY WITH PRESSURE RELEASE SERIES 27 - Manual

2 © 2009, ROSS CONTROLS ® . All Rights Reserved.
Pressure Controlled Pilot Operated Check Valves
TYPICAL APPLICATION
In the schematic diagram at the right, two single PO check valves (Type A or B) are
used in a typical cylinder circuit. Their function is to provide automatic stopping of
the cylinder if either electrical or pneumatic power is lost. This circuit can also be
used for jogging the cylinder as well as providing for an emergency stop.
In certain port sizes the two check valves could be replaced by just one Type C dual
PO check valve. The dual PO check valve contains the functions of two individual
checks in a single compact housing, and eliminates the need to connect externally
the inlet of one check to the pilot of the other.
CHECK
VALVE CHECK
VALVE C1 C1
Pilot Pilot
V1 V1
OPERATING
VALVE
Exhaust Exhaust
CYLINDER
STANDARD SPECIFICATIONS: For valves on this page.
Ambient/Media Temperature: 40° to 175°F (4° to 80°C).
Flow Media: Filtered air; 5 micron recommended.
Inlet Pressure: 15 to 150 psig (1 to 10 bar).
Signal Pressure: Must be equal to or greater than inlet.
Port Threads: NPT standard, BSPP. For BSPP threads add a
“D” prefix to the model number, e.g., D2751A2908.
B
C
A
Valve Port Valve Model Avg. C
V
Dimensions inches (mm) Weight
Type Size Number (Fully open) A B C lb (kg)
1/4 2751A2908 2.2 1.5 (38) 3.6 (91) 2.0 (51) 2.3 (1.0)
A 3/8 2751A3908 2.9 1.5 (38) 3.6 (91) 2.0 (51) 2.3 (1.0)
1/2 2751A4915 3.2 1.5 (38) 3.6 (91) 2.5 (64) 2.3 (1.0)
1/4 2751A2903 2.3 3.6 (91) 3.8 (95) 3.1 (79) 1.3 (0.6)
B 3/8 2751A3901 3.8 3.6 (91) 3.8 (95) 3.1 (79) 1.3 (0.6)
1/2 2751A4902 4.0 3.6 (91) 3.8 (95) 3.1 (79) 1.3 (0.6)
1/2 2751A4905 7.7 4.6 (116) 4.4 (112) 3.1 (79) 2.3 (1.0)
B 3/4 2751A5903 9.0 4.6 (116) 4.4 (112) 3.1 (79) 2.3 (1.0)
1 2751A6901 9.0 4.6 (116) 4.4 (112) 3.1 (79) 2.3 (1.0)
1 2751B6904 24 6.7 (169) 6.5 (165) 4.1 (104) 6.0 (2.7)
B 11/4 2751B7901 29 6.7 (169) 6.5 (165) 4.1 (104) 6.0 (2.7)
11/2 2751B8902 29 6.7 (169) 6.5 (165) 4.1 (104) 6.0 (2.7)
3/8 2768C3900 2.9 3.4 (89) 3.7 (94) 2.4 (61) 2.0 (0.9)
C 1/2 2768C4900 3.2 3.4 (89) 3.7 (94) 2.4 (61) 2.4 (1.1)
Dual 3/4 2768C5900 8.5* 4.4 (111) 4.1 (104) 3.0 (76) 3.8 (1.7)
1 2768A6900 8.5* 5.8 (147) 4.1 (104) 3.9 (99) 6.8 (3.1)
*Effective C
V
varies with load and pressure drop. Consult ROSS for specifics on your system.
Type A Single
PO Check Valve
Ports: 1/4 through 1/2
Type B Single
PO Check Valve
Ports: 1/4 through 1 1/2
Type C Dual
PO Check Valve
Ports: 3/8 through 1
IMPORTANT NOTE: Please read carefully and thoroughly all of the CAUTIONS on page 11.
PIPING NOTE FOR TYPE B VALVES
Port 1 should be piped to the cylinder,
and port 2 to the operating valve.
WITHOUT Trapped Pressure Relief Function
• Can be used wherever a high-flow or remotely-controlled checking
function is needed.
• Can be used in a circuit to provide automatic stopping of a cylinder
in the event of the loss of electrical or pneumatic power.
• Also available with an automatic exhausting function, remote and
manual trapped pressure relief function, or solenoid dual pilot
operated check.
Single Pilot Operated Check Valve with
trapped pressure relief illustrated
Series 27 Pilot Operated Check Valves