PrimeLine™ Pump Replacement Parts

  • Our majority of check valves are self-priming, no external priming valve/syringe required
  • Designed to deliver superior flow stability and accuracy
  • Crush proof cartridge makes routine maintenance quick and easy
  • Pistons are engineered to insure a high quality surface finish
  • Seals are designed for long life, wide range of solvent compatibility, and optimum performance

Why ASI Check Valves are the Best?

Because ASI Spring Loaded Check Valves insure the reliable, repeatable operation and response time and more.


With the ASI check valve, priming is easy.  Open the pump outlet to release backpressure on the pump, and turn on the pump.  Your pump will prime itself, even if the head and intake lines are completely dry.  You won't need to use syringes or draw-off valves to prime your pump.

Superior Flow Rate Stability

Because of the rapid and repeatable closure rate of the valve, the ball returns to the seat and seals before solvents have a chance to flow back through the valve.  The result is a flow rate that is extremely repeatable and accurate, which means more repeatable retention times.   

Acetonitrile-resistant Valves

One of the headaches when using Acetonitrile is the tendency for the ball and seat to get stuck - actually bonded - in the closed position.  The frequency of this frustrating phenomenon depends on a number of factors, including the surface finish and condition of the ball and seat.  The R & D team at ASI has developed a new check valve that will not bond shut in the presence of Acetonitrile even when immersed and unused for days or weeks at a time.  We offer the same self-priming, rapid closure that ASI check valves have always been known for.  Acetonitrile-resistant Valves are now available for all Check Valve Cartridges that we currently offer including Waters, Agilent and other brands.  If your customer is using Acetonitrile, even ln low concentration, then we recommend ASI Acetonitrile-resistant Valves.  These work as well as the ruby/sapphire valves in any mobile phase, so there is no disadvantage to their use.  Please simply add ”ACN” at the end of the current P/Ns to order.  

The wetted materials used in our ACN valve are identical to our standard valve. It is not the materials, but rather how we use the materials that make the valve tolerant of ACN.  

UHPLC and SFC Applications are Available 

Please contact us for the more information.

Rugged Construction

The ASI check valve will not crush, crack or leak due to high pressure.  We designed the ASI cartridge so that loads are transmitted through the valve casing rather than through the seat, as in conventional valves.  The result is a valve that can withstand up to a 10,000 PSI continuous operating pressure, and will never fail no matter how much you tighten the housing (go ahead and try it -- it's guaranteed!).  High pressure valves, up to 15,000 PSI, are also available.   


ASI check valves we ship must pass three stringent tests before it is shipped.
These tests are by far the most stringent in the HPLC industry, and indeed it is unlikely that any other valves would even pass these tests. But we do all these tests because we know how important it is to make sure that when you put a new valve in your pump, it will perform properly. After all, HPLC is hard enough as it is without worrying about your check valves!

1) Self-prime Test

This test uses a special pump test fixture that simulates an HPLC pump to verify that the valve is self-priming.  After the test pump and intake line are purged of water, the valve must operate well enough so that the pump can draw water from a reservoir that is 36 inches below the pump intake.  If the valve fails to prime, or "skips" even once during this test, it is rejected.  This test not only guarantees that the valve will prime, but also that the valve will perform properly even at very low pressures, where most other valves do not work well.

2) High Pressure Leak Test

The valve is pressurized to 12,000 PSI and tested for leakage. Valves that exceed 50 nano liters per minute are rejected. This test not only insures valve integrity at very high pressures, but it also insures that the valve will still function properly even when the customer inadvertently over tightens the valve housing. We do not monitor nitrogen bubbles to measure leak rate, because a liquid can leak due to capillary action whereas gas will not. Besides, the chromatographer is pumping liquids, not gas!

3) Low Pressure Leak Test

The valve is pressurized to 500 PSI and tested for leakage. Valves that exceed 50 nano liters per minute are rejected. Most valves have difficulty closing and sealing properly in the absence of the large closing forces due to high pressure. ASI valves are designed so that they do not require any backpressure to operate properly, and this test verifies it.

Convenient and Economical Cartridge Design

When it's time for routine maintenance, you only replace the cartridge, not the entire assembly.  The ASI cartridge costs no more than most conventional valve rebuild kits, and you won't spend time chasing balls all over the lab bench.


Pump Replacement Parts Brochure

Why you need to buy Check Valves from us

Why you need to buy Pistons from us

Selection Guide for material of piston seals

ASI Self-priming CVs Installation Instruction