RPM low-pressure regulators (from 5 mbar)

New series

RPM low-pressure regulators by AirCom reduce the pressure of compressed air from the air network to a very low value – from 5 mbar, i.e. 0.005 bar, up to 1500 mbar. They have a large diaphragm, so they detect even a small change in pressure and keep the outlet constant.

At the inlet, you connect a standard air network with a pressure of 1 to 15 bar. Two sizes – RPM 12 with a G 1/2" connection and RPM 10 with a G 1" connection – cover flow rates of 1,000 to 9,600 l/min. The regulators have no air consumption of their own, and a ⌀ 63 mm pressure gauge with a scale to match the range is included.

What the RPM regulators offer

• control from 5 mbar (0.005 bar) to 1500 mbar in 7 ranges
• the large diaphragm with PTFE holds a constant pressure even at a low set pressure
• inlet pressure 1 to 15 bar – you connect them directly to the air network
• no air consumption of their own – when no air is consumed, no air escapes
• ⌀ 63 mm pressure gauge included, scale in mbar or bar depending on the range
• pressure gauge connection G 1/4" on both sides, any mounting position
• the setting is secured with a lock nut against unintentional adjustment
• painted aluminium body, stainless steel spring housing, FKM O-rings

All RPM low-pressure regulators

Flow rate according to the manufacturer at an inlet pressure of 6 bar and the maximum outlet pressure of the range. Dimensions: diameter of the diaphragm cover × overall height.

How to choose an RPM regulator

1. Units. 1 bar = 1,000 mbar. A pressure of 45 mbar is therefore 0.045 bar, and 400 mbar is 0.4 bar.
2. Range according to the pressure you need. Choose the smallest range that your pressure fits into. In a smaller range, the pressure can be set more finely and the pressure gauge has a finer scale. For 30 mbar, the 5–45 mbar range is suitable; for 300 mbar, the 10–400 mbar range.
3. Size according to the flow rate. RPM 12 (G 1/2") handles 1,000 l/min. RPM 10 (G 1") handles 1,400 l/min in the ranges up to 400 mbar and 9,600 l/min in the 15–700 and 200–1200 mbar ranges.
4. Inlet pressure. The inlet pressure must be at least 1 bar and no more than 15 bar.

Example: you need a constant 300 mbar at an air consumption of up to 600 l/min, with 7 bar in the air network. RPM 12 with the 10–400 mbar range is sufficient – this is RPM12-400. For the same pressure and an air consumption of 5,000 l/min, choose RPM10-700 (15–700 mbar, 9,600 l/min).

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How a low-pressure regulator works

1. With the handwheel (RPM 12), the adjusting screw or the T-handle (RPM 10), you compress the spring. The spring presses on the large diaphragm, which opens the valve – air flows from the inlet to the outlet.
2. The outlet pressure acts on the diaphragm from below. The large diaphragm reacts even to a small change in pressure: the valve closes or opens slightly and lets through only as much air as is being consumed.
3. The regulator has no secondary venting. When you reduce the set pressure, the outlet pressure drops only as air is consumed – air must therefore be able to flow away downstream of the regulator.
4. With no air being consumed, the valve is closed and no air escapes – the regulator has no air consumption of its own.

Flow curve

The manufacturer’s graph for RPM 12 with the 20–1000 mbar range at an inlet pressure of 10 bar. The lines start at a set pressure of 200, 450 and 700 mbar. As the flow rate increases, the outlet pressure drops by only 30 to 70 mbar.

Dimensions

Installation and adjustment

• install a compressed air filter upstream of the regulator – the manufacturer recommends it; the internal strainer only provides protection during installation
• blow out the pipework before installation; dirt would damage the valve seat
• connect the regulator according to the arrow on the body (IN → OUT); any mounting position is possible; do not use lubricant during installation
• screw the pressure gauge into one of the side connections G 1/4" and close the other one with the supplied plug
• before pressurising for the first time, release the setting so that the spring is not tensioned; then always set the pressure by increasing it, i.e. from below
• secure the setting with the lock nut
• RPM 12 can be fixed to a wall or frame with the mounting bracket RPMW

Accessories and spare parts

For RPM 12 regulators, there is the stainless steel mounting bracket RPMW. The manufacturer does not supply a bracket for RPM 10; it is mounted directly in the pipework. Please ask us about a spare diaphragm or a repair kit. You will find parts for other regulators in the category spare parts and accessories for pressure regulators.

Series specifications

What does mbar mean?

A millibar is a thousandth of a bar: 1 bar = 1,000 mbar. A regulator with a range of 5–45 mbar therefore sets 0.005 to 0.045 bar.

Why does the outlet pressure not drop immediately when I reduce it?

RPM regulators have no secondary venting. The outlet pressure drops only once the air downstream of the regulator has been consumed or has flowed away.

Is the pressure gauge included?

Yes, a ⌀ 63 mm pressure gauge. The range of its scale is given for each regulator in the table above and on the product page.

What pressure must there be at the inlet?

At least 1 bar and no more than 15 bar.

Why does RPM 10 have two different flow rates?

The 15–700 and 200–1200 mbar ranges have a larger valve (Kv 8.4 m³/h) and a T-handle, so they handle 9,600 l/min. The ranges up to 400 mbar have Kv 1.4 m³/h and a flow rate of 1,400 l/min.

Can I use the regulator for a gas other than air?

The manufacturer specifies it for compressed air and neutral gases. The manufacturer has special versions for other gases, so please ask us before ordering.

Technical data according to the manufacturer AirCom. Flow rate at an inlet pressure of 6 bar and the maximum outlet pressure of the range, flow curve at an inlet pressure of 10 bar.

You will find more regulators in the category air pressure regulators.