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ProAir PCP Hand Pump 4500 – Use, Pressure and Safety

ProAir Biathlon PCP Pump 4500 – Use, Pressure and Safety

This guide explains how to use the ProAir Biathlon PCP Pump 4500 safely and correctly. It covers connection, pressure-gauge readings, filling procedures and why the high-pressure hose must always be depressurised before the filling probe is removed.

ProAir Biathlon PCP Pump 4500 for filling PCP air rifles
ProAir Biathlon PCP Pump 4500 for manually filling compatible PCP air rifles and air cylinders.
4500 PSI Approximately 310 bar
31 MPa Approximately 310 bar
Forster coupling Fitted to the high-pressure hose

The filling probe is not included

The pump is supplied with a Forster coupling on the high-pressure hose. The filling probe required for the air rifle or air cylinder must be purchased separately.

Always make sure that the filling probe is compatible with both the pump coupling and the filling port on the rifle or air cylinder.

What is a PCP hand pump?

A PCP hand pump is used to fill the air cylinder of a pre-charged pneumatic air rifle. PCP stands for Pre-Charged Pneumatic.

The pump compresses air through repeated strokes. The pressure rises gradually in the high-pressure hose and air cylinder. Pumping resistance therefore increases as the pressure rises.

A hand pump is a portable alternative to a compressor or an external compressed-air cylinder. It can be used at home or at the shooting range, provided that the correct connection is used and the manufacturer's pressure limits are followed.

The pump capacity is not the rifle's permitted pressure

A pump rating of up to 4500 PSI does not mean that every air cylinder may be filled to this pressure.

Always follow the maximum filling pressure stated on the air cylinder, rifle or in the manufacturer's documentation. Never exceed this limit.

Main components of the pump

ProAir PCP hand pump with handle, pressure gauge, hose and footplate
  1. Handle: used to move the pump up and down.
  2. Pump cylinder: compresses the air during pumping.
  3. Pressure gauge: displays the pressure in the filling system.
  4. Bleed screw: releases the remaining pressure from the high-pressure hose after filling.
  5. High-pressure hose: carries compressed air from the pump to the filling probe.
  6. Forster coupling: the coupling on the high-pressure hose into which a compatible filling probe is connected.
  7. Footplate: keeps the pump stable during use.

Forster coupling, filling probe and filling port

It is important to distinguish between the pump coupling, the filling probe and the filling port on the rifle.

Forster coupling
The coupling fitted to the pump's high-pressure hose. A compatible filling probe is connected to this coupling.
Filling probe
The separate connector that attaches to the pump's Forster coupling and is inserted into the filling port of the rifle or air cylinder. The filling probe is not included with the pump.
O-rings
The filling probe normally has two O-rings that seal against the inside of the filling port. The O-rings must be intact, clean and correctly positioned.
Filling port
The opening or connection on the rifle or air cylinder into which the filling probe is inserted.
Bleed screw
The screw that is opened after filling to depressurise the high-pressure hose.
Pump High-pressure hose Forster coupling Separate filling probe Filling port Air cylinder
Forster coupling on the pump hose and separate PCP filling probe
The Forster coupling is fitted to the pump hose. The filling probe must be purchased separately.
PCP filling probe with two O-rings
The two O-rings on the filling probe seal against the inside of the filling port.

How to read the pressure gauge

The pump pressure gauge is marked in PSI and MPa. Many air rifles and air cylinders, however, specify the filling pressure in bar.

You may therefore need to convert the stated pressure before you begin pumping.

Quick pressure conversion

  • 1 MPa = 10 bar
  • 1 bar ≈ 14.504 PSI
  • 100 bar = 10 MPa ≈ 1450 PSI
  • 200 bar = 20 MPa ≈ 2901 PSI
BarMPaApproximate PSI
50 bar5 MPa725 PSI
100 bar10 MPa1450 PSI
150 bar15 MPa2176 PSI
180 bar18 MPa2611 PSI
200 bar20 MPa2901 PSI
210 bar21 MPa3046 PSI
230 bar23 MPa3336 PSI
250 bar25 MPa3626 PSI
300 bar30 MPa4351 PSI
310 bar31 MPa4496 PSI

Example: FX Airguns Biathlon

For an FX Airguns Biathlon air rifle with a stated maximum filling pressure of 210 bar, the maximum pressure is equivalent to:

  • 210 bar
  • 21 MPa
  • approximately 3046 PSI

Stop pumping when the gauge reaches 21 MPa or approximately 3050 PSI. Do not fill the air cylinder above 210 bar.

Always check the marking on the cylinder being filled

The example above only applies to a cylinder or model that is actually marked for a maximum filling pressure of 210 bar.

Other rifles and air cylinders may have different pressure limits. Always check the marking and the manufacturer's instructions before filling.

Pressure gauge on a ProAir PCP pump marked in PSI and MPa
Consider marking 21 MPa and approximately 3050 PSI in the image to show where 210 bar is read.

Check the equipment before filling

  • Make sure the pump is correctly assembled and standing securely.
  • Check the high-pressure hose for visible damage.
  • Make sure the Forster coupling is clean and undamaged.
  • Check that the filling probe is suitable for the rifle.
  • Check that the filling probe fits the pump's Forster coupling.
  • Make sure both O-rings on the filling probe are intact and clean.
  • Check that the rifle's filling port is free from dirt.
  • Confirm the air cylinder's maximum filling pressure.
  • Make sure the pump pressure gauge reads zero before connection.
  • Check that the bleed screw can be opened and closed.

Do not use equipment with visible damage

Do not use the pump if the hose, pressure gauge, coupling or any other high-pressure component is damaged, loose or deformed.

Stop using the pump if you notice an abnormal leak or if the pressure gauge does not operate as expected.

How to fill the air cylinder step by step

Check the maximum filling pressure

Read the marking on the air cylinder or consult the rifle manufacturer's instructions. Decide before pumping at which gauge reading you must stop.

Select the correct filling probe

Use a filling probe that is compatible with both the rifle's filling port and the pump's Forster coupling. The filling probe must be purchased separately.

Inspect the O-rings

Make sure both O-rings are intact, clean and correctly positioned. Do not use the filling probe if an O-ring is missing, cracked or deformed.

Connect the probe to the Forster coupling

Connect the filling probe to the coupling on the high-pressure hose. Make sure the coupling has locked and that the probe is securely connected.

Insert the probe into the filling port

Insert the filling probe straight into the filling port on the rifle or air cylinder. Avoid twisting or angling the probe, as this may damage the O-rings.

Close the bleed screw

Close the bleed screw gently by hand so that the system can build pressure. Do not overtighten it.

Pump slowly and steadily

Use long, smooth strokes and the pump's full stroke length. Pumping resistance will increase as the pressure rises.

Monitor the pressure gauge

Read the correct scale throughout the filling process. Stop pumping when the permitted filling pressure has been reached.

Open the bleed screw

Slowly open the bleed screw when filling is complete. A hissing sound will be heard as pressure is released from the high-pressure hose.

Wait until the hose is depressurised

Wait until the hissing sound has stopped and the pressure gauge has returned towards zero. Do not remove the filling probe until the high-pressure hose has been depressurised.

Remove the filling probe

Pull the filling probe straight out of the filling port. The probe can then be disconnected from the Forster coupling if required.

Why must the hose be depressurised?

Never remove the probe while the hose is pressurised

After the air cylinder has been filled, compressed air remains inside the pump's high-pressure hose.

If the filling probe is pulled from the filling port while the hose is still pressurised, the probe's O-rings are forced firmly against the inside and edge of the filling port.

Pulling the probe out under pressure can cut, deform or prematurely wear the O-rings. Damaged O-rings may cause leakage during the next filling operation.

 Always open the bleed screw and wait until all pressure has been released before removing the filling probe. 

Bleed screw on the ProAir PCP hand pump
Open the bleed screw slowly after filling.

Correct pumping technique

Pumping becomes more difficult as the pressure in the air cylinder rises. Controlled movement makes the process easier and reduces unnecessary strain on both the user and the pump.

  • Place both feet securely on the footplate.
  • Keep the pump upright.
  • Use the full pump stroke.
  • Pump slowly and smoothly.
  • Avoid short, fast or jerky strokes.
  • Use your body weight as resistance increases.
  • Take a break if the pump becomes very hot.
  • Check the pressure gauge regularly while pumping.
Correct technique when using a PCP hand pump
Stand securely and use slow, full pumping strokes.

Cleaning, inspection and storage

A clean and properly maintained pump is easier to inspect and less likely to develop problems caused by dirt, moisture or damaged seals.

After each use

  • Make sure the high-pressure hose is depressurised.
  • Wipe the pump with a clean, dry cloth.
  • Clean the Forster coupling.
  • Clean the separate filling probe.
  • Inspect the O-rings on the filling probe.
  • Protect the coupling and connections from dirt.
  • Store the pump in a clean, dry and protected location.

Inspect regularly

  • The high-pressure hose and its attachment points.
  • The function and locking of the Forster coupling.
  • The O-rings on the filling probe.
  • The function of the bleed screw.
  • The pressure gauge and its mounting.
  • The footplate, handle and pump fasteners.

Follow the manufacturer's instructions for servicing

Do not perform advanced disassembly or internal repairs without verified instructions for the specific pump model.

Only use lubricants and replacement parts suitable for the pump's materials, seals and high-pressure system.

Cleaning and inspection of a PCP filling probe and O-rings
Replace O-rings that are cracked, cut or visibly deformed.

Troubleshooting

ProblemPossible causeSafe check
The pump does not build pressureThe bleed screw may be open or one of the connections may be leaking.Check the bleed screw, hose, Forster coupling, filling probe and O-rings.
Air leaks at the filling portThe probe may be incorrectly positioned or an O-ring may be damaged.Stop pumping, depressurise the hose and inspect the probe and both O-rings.
The probe is difficult to removePressure probably remains in the high-pressure hose.Open the bleed screw and wait until the hissing sound has stopped.
The probe is loose in the couplingThe coupling may not have locked correctly or the probe may be incompatible.Stop using the pump and check compatibility. Do not pump unless the connection is secure.
Pumping becomes progressively harderThe pressure inside the air cylinder is increasing.This is normal within the permitted pressure range. Continue slowly and monitor the pressure gauge.
The pressure gauge shows nothing or appears incorrectThe system may be leaking or the gauge may be damaged.Stop using the pump. Inspect visible connections and do not continue if the gauge operation is uncertain.
The O-rings are frequently damagedThe probe may be removed under pressure, inserted at an angle or be the wrong size.Always depressurise before removal. Check probe compatibility and insert it straight.

When to stop using the pump

Do not continue pumping if the hose is damaged, the coupling is loose, the pressure gauge is faulty, there is a major leak or the high-pressure system is not operating normally.

Contact Skidskytteexperten or a qualified technician before using the pump again.

Frequently asked questions about the ProAir PCP hand pump

    Is the filling probe included with the pump?    

No. The filling probe must be purchased separately and selected according to the rifle or air cylinder being filled.

 
    What type of coupling is fitted to the pump hose?    

The high-pressure hose is fitted with a Forster coupling for connecting a compatible filling probe.

 
    What does 210 bar equal on the pressure gauge?    

210 bar equals 21 MPa and approximately 3046 PSI. On the pump pressure gauge, this can therefore be read as 21 MPa or approximately 3050 PSI.

 
     What pressure should an FX Airguns Biathlon be filled to?     

An FX Airguns Biathlon marked with a maximum filling pressure of 210 bar must not be filled above 210 bar. This equals 21 MPa or approximately 3046 PSI. Always check the marking on the actual air cylinder.

 
    Must the hose be depressurised after every filling?    

Yes. Open the bleed screw and wait until the hose is fully depressurised before removing the filling probe.

 
    Why is there a hissing sound?    

The hissing sound is compressed air being released from the high-pressure hose when the bleed screw is opened.

 
    Why can the O-rings become damaged?    

The O-rings can be damaged if the probe is removed while the system is pressurised, if the probe is inserted at an angle or if an incorrect connector is used.

 
    Can the pump be used with all PCP air rifles?    

The pump requires a filling probe that is compatible with both the Forster coupling and the filling port on the rifle. The rifle's permitted filling pressure must also be observed.

 
    Is 4500 PSI the same as 4500 bar?    

No. 4500 PSI equals approximately 310 bar or 31 MPa.

 
    What should I do if the pump leaks?    

Stop pumping and depressurise the system. Inspect the visible connections, filling probe and O-rings. Do not use the pump if the cause is unclear or if any high-pressure component is damaged.

 

Summary

The ProAir Biathlon PCP Pump 4500 is a manual high-pressure pump for filling compatible PCP air rifles and air cylinders. The high-pressure hose is fitted with a Forster coupling.

The filling probe is not included and must be purchased separately. It must be compatible with both the pump coupling and the filling port on the rifle.

The pump pressure gauge is marked in PSI and MPa. A pressure of 210 bar equals 21 MPa or approximately 3046 PSI.

The most important procedure after filling is to open the bleed screw and fully depressurise the high-pressure hose before the filling probe is removed. This protects the O-rings and reduces the risk of leakage.