Airtac M5PM Mushroom Push Button Type Mechanical Valve M5PM21008B
Mechanically actuated · no coil, no pilot airThe AirTAC Airtac M5PM Mushroom Push Button Type Mechanical Valve M5PM21008B is a genuine 5/2-way mushroom head type control valve. A large mushroom head that can be hit with a palm without looking for it. It is an external control, direct-acting valve - the spool is moved mechanically, so there is nothing to wire and no pilot line to plumb. Ports are PT1/4 with a 12.0 mm2 (Cv 0.67) effective area.
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Specifications
| Model | M5PM21008B |
|---|---|
| Valve type | 5/2 way, external control, direct acting |
| Actuation | Mushroom head type |
| Reset | Automatic (spring) restoration |
| Body series | 200 Series, single control |
| Port size | PT1/4 |
| Effective area | 12.0 mm2 (Cv 0.67) |
| Button colour | Black |
| Fluid | Air, filtered by a 40 um element |
|---|---|
| Pressure range | 0 - 1.0 MPa (0 - 145 psi) |
| Proof pressure | 1.5 MPa (215 psi) |
| Temperature | -20 to +70 C |
| Body material | Aluminium alloy |
| Lubrication | Not required |
| Thread standard | PT (Rc tapered) |
| Spool stroke | 2.0-3.3 mm |
| Actuator stroke | 3.8-5.1 mm at the button |
Sliding-column (spool) construction, so operating force is not affected by working pressure - there is no back-pressure effect. Lubrication is not required, but once the valve has been run on lubricated air it must stay on lubricated air; AirTAC suggests ISO VG32 or equivalent. The control set is engineering plastic and must be operated by hand only - never switch it by striking it with a tool. The exhaust outlet sits on top of the body, so a silencer fits directly.
About the M5PM21008B
The M5PM21008B is a 5/2-way mechanical control valve, not a solenoid valve. There is no coil, no wiring and no pilot port: a large black mushroom head on a 200-series single-control body is struck with a palm or fist and the direct-acting spool changes over on the spot. When the palm comes away, the automatic spring snaps the spool back to its rest position, releasing the downstream signal.
The port size is PT1/4 and the effective area is 12.0 mm2 (Cv 0.67), the largest flow in the M5 common-type range, so it feeds 1/4-line cylinders without a bottleneck. Because the spool is a sliding-column design, the force needed to change over does not rise with working pressure, so the head feels identical to hit at 0.2 MPa as it does at 1.0 MPa. A welcome installation detail: the exhaust port sits on top of the body, so a silencer screws straight in without re-plumbing.
Typical applications
Bench press clamp initiation
Mounted at the front of a small pneumatic bench press, the operator palms the mushroom head to start the clamp stroke and the spring return vents the signal the moment the hand lifts - a natural hold-to-run gesture.
Fixture changeover on machining jigs
Fitted to a milling or drilling jig, a quick palm strike energises the clamp cylinders; spring return dumps them instantly so parts can be swapped between cycles without levers or buttons to hunt for.
Packaging machine jog station
On a carton-sealing or filling line, maintenance staff nudge the mushroom head to jog a conveyor section or actuator a single step, the 5/2 reversal feeding the cylinder and the spring venting it on release.
How to choose
Choose the mushroom head over the M5PP protruding button or M5PF flat button when the operator must find and hit the control fast and without looking - the mushroom gives the biggest target of the three. If the valve must instead HOLD its state after actuation, leave the spring-return family entirely and look at the M5PL latching or M5HS selector type.
On flow, a 110-body 1/8in valve offers only 8.0 mm2 (Cv 0.45); this 210 body at 1/4in doubles that to 12.0 mm2 (Cv 0.67), so match the port to the cylinder bore. Mind the reversal stroke: the spool travels 2.0-3.3 mm and the button 3.8-5.1 mm. Exceeding these figures by striking too hard or with a tool damages the valve - AirTAC states this explicitly, and the mushroom head is meant for a palm, never a hammer.
Frequently asked questions
It is a 5/2-way external-control, direct-acting mechanically actuated valve with a mushroom head and automatic spring return, in a 200-series (210) single-control body with PT1/4 ports and a black button. Effective area is 12.0 mm2 (Cv 0.67). Operating pressure is 0-1.0 MPa (0-145 psi), proof pressure 1.5 MPa (215 psi) and temperature range -20 to +70 C. Media is air filtered by a 40 um element; lubrication is not required, though ISO VG32 oil is suggested if lubricated air is already in use.
The published reversal stroke is 2.0-3.3 mm at the spool and 3.8-5.1 mm at the button. These are limits, not adjustment ranges: driving the head past them deforms the mechanism and damages the valve. Strike it squarely with a palm, and never with a tool - the mushroom head uses an engineering-plastic control set that AirTAC rates for manual operation only. Body or panel mounting both work, and the top-mounted exhaust takes a silencer directly.