The Marsh Bellofram Type 70BP back pressure air regulator is a high-flow, high-precision pneumatic relief valve with adjustable set point. It is expressly designed for applications requiring high flow capacity and accurate pressure controls. It may be used in place of a standard relief valve to improve pressure control while maintaining protection against over-pressurization of supply pressure lines to instruments and other control devices.

The Type 70BP is most often used in conjunction with diaphragm-operated valve and bleed orifice as a compressor controller. Excess compressor pressure is relieved through the regulator to actuate the intake restricting valve. When the regulator is shut off, downstream air escapes through the bleed orifice, allowing the restricting valve to open. Units are designed to respond quickly to minute changes in upstream pressure. Incorporation of a patented Bellofram rolling diaphragm design offers reliable performance over millions of cycles. Stack up construction may be disassembled and serviced without removal from the air line, thus reducing downtime.

Applications
· Precision High-Flow Back Pressure Relief
· Precise Control of Paper Machinery Felt Guides
· Pneumatic Clutch Regulation
· Pressure Cylinder Control
· Protection of Instrument and Control Device Supply Pressure Lines