Frequently Asked Questions:

Model Numbers preceded by letters „D“ or „C“, respectively, characterize parallel threads according to ISO 228/1. Other thread types are available. Please contact ROSS for details.

The valve symbols shown in our documentation are designated in accordance with specifications of International Organization for Standardization, ISO 1219, 1976. Valve ports comply with ISO/TC 131, CETOP recommendation RP 86, amendment 1975.05.05.
1 (P) is the inlet or supply port.
2 (A) is an outlet port.
3 (R) is an exhaust port.
4 (B) is an outlet port.
5 (S) is an exhaust port.

The first figure defines the number of pneumatic ports, the second defines the number of valve positions.

Example: A 2/2 way valve has 2 outlet ports and is designed to take 2 positions.

NC - „Normally Closed“ means that the valve is in closed position when no energy is supplied.
NO - „Normally Open“ means that the valve is in the open position when no energy is supplied.

In case of a valve with internal pilot supply, compressed air for the control of the pilot valve is internally diverted from the main air supply (1). In case of a valve with external pilot supply, compressed air for the pilot valve is supplied through a separate port at the valve or sub-base.

Nominal diameter refers to the narrowest area in the valve, in most cases this is the valve seat. While the port size may be G 3/4, the ND may be only 0.8 mm.

The formula to be used for flow calculation, can be found here.

It is preferred that the valves be mounted with the pilot section up, but sideways and upside-down is okay.

Although, compressed air is the usual medium, nitrogen, carbon dioxide, argon or any inert gas can be used. Please ask your ROSS service point or Technical Services at ROSS for details.

Ross offers valves specifically suited and designed for vacuum service. Please check for further information with your ROSS service point or Technical Services at ROSS.

Our valves are designed to operate on compressed air. If the application requires the valve to control the flow of a liquid, please contact your ROSS service point or Technical Services at ROSS

AC is the abbreviation for Alternating Current; e.g. 230V power supply in households. DC means Direct Current; e.g. 12 V/ DC supply for the car.

ROSS valves are available for all standard voltages and a number of other voltages. For any specific voltages, please contact your ROSS service point.

Specific spare parts are available for many ROSS valves. We offer ROSS seal kits (including all sealing elements) or service kits (including seals and moving parts), respectively.

All valves can be sent to ROSS EUROPA’s repair-and-service department at the company’s headquarters in Langen. Here the valve is checked and repaired by experienced pneumatics experts, newly granted functional warranty is issued. If repair is found to be not reasonable, it is recommended to buy a new, fully warranted valve.

If a new valve body is required for the valve, it would be better to purchase a new valve with full warranty.

If you are having problems getting your EEZ-ON® valve to shift to the full open position, there are a couple of things that may be the cause of the problem.

1. The downstream volume you are trying to fill may be too large. When the EEZ-ON® valve is signaled to shift to the on position, it initially bypasses air downstream through a metered orifice. The metering is adjusted by turning the adjusting needle: Turning the adjusting needle counterclockwise increases the flow through the orifice by opening the orifice wider. The maximum flow through the bypass orifice is 30%. The EEZ-ON® requires the downstream pressure to fill up to approximately 50% of inlet pressure, then the valve opens fully. Of course, the larger the volume to be filled downstream, the longer the valve will take to shift. If the main supply air is dumped, the process starts over.
2. A similar situation occurs when there are leaks downstream that add up to a leak larger than the flow through the bypass orifice in the EEZ-ON® valve. Essentially, the downstream air can escape to atmosphere faster than the bypass orifice can build pressure downstream. The result is an EEZ-ON® valve that won’t shift. On very large systems, the leaks may be small, but the sheer number of leaks add up. Another thing to look for is devices that constantly leak by, such as air motors. In the case of an air motor, an isolating valve might have to be installed so that the motor can be shut off until full system pressure is achieved.

Such an effect may occur, when sticking friction is much larger than sliding friction of the piston in the cylinder tube. This effect, commonly known as “stick-slip-effect”, is triggered by air supply of the cylinder below normal level. In order to avoid this effect, cylinder exhaust air is adjusted through speed control valves. Adjustment of supply air must be avoided.

A base-mount valve / manifold conforming to the ANSI standard (American National Standards Institute).

See Bulletin 331G "Service and Installation Manual" for instructions.

No, these are the pilot exhaust ports. Plugging these ports, results in valve malfunction. In order to avoid contamination, we recommend to use a silencer.

These are the port markings for the mounted valve.
1 (P) is the inlet or supply port.
2 (A) is an outlet port.
3 (R) is an exhaust port.
4 (B) is an outlet port.
5 (S) is an exhaust port.

The ANSI valve has two sets of wires, two are black and two are white. The two black wires go to the control 14 pilot and the two white wires go to the control 12 pilot. If you have a single solenoid valve, you only need the two black wires. This information is also inside the conduit cover of the ANSI base or manifold.

ISO is the abbreviation for „International Standards Organization“. ROSS ISO valves conform to a specific mounting footprint set forth by the ISO organization.

These are port markings for the mounted valve.
1 (P) is the inlet or supply port.
2 (A) is an outlet port.
3 (R) is an exhaust port.
4 (B) is an outlet port.
5 (S) is an exhaust port.

If the DM2 does not shift after start-up, but takes the “lock-out” position instead, air supply should be verified, and piping to the valve is recommended to be checked for correct dimension. The DM2 valve requires 2-8 bar, volume flow in the adequate nominal size.

The valve is locked out and must be reset with at least 4.2 bar air.

The E-P monitor valve is equipped with pneumatic sensing and electric reset.
The L-G monitor valve is equipped with pneumatic sensing and pneumatic reset.
The D-S monitor valve is designed for electronic sensing and is reset by closing a dry switch.

A monitor lock-out occurs when the main piston assemblies inside the valve body fail to move at the same time. The reason could be air-line contamination, overlubrication, burnt out solenoid or actual internal parts failure. Please see the valve service bulletin for more information about your particular style of valve. Your local distributor can send you the bulletin, or contact Customer Service at ROSS EUROPA.

Valid accident prevention legislation requires air-controlled clutch-and-brake systems in power presses to be equipped with monitored double valves, so that in case of a valve failure any further press cycle will be ruled out. Most ROSS double valves are certified by the competent accident preventation bodies (e.g. Deutsche Gesetzliche Unfallversicherung/BG – German Accident Prevention Authority).

Plugging the pilot exhaust port will cause erratic valve operation. In order to avoid contamination, it is recommended to use a silencer.

These are port markings. X-1 is the pilot external supply port. Y-3 is the pilot exhaust port.

These are valve port markings.
1 (P) is the inlet or supply port.
2 (A) is an outlet port.
3 (R) is an exhaust port.
4 (B) is an outlet port.
5 (S) is an exhaust port.

This is a simple procedure. Please see Bulletin 331G, Service and Installation ManualG for instructions.

Conversion is not possible. The internal passages and parts of a 3-way normally closed valve are shaped differently than those of a 3-way normally open valve.

Such a conversion is not possible. Blocking port 3 will result in valve malfunction.