On/Off and Prime/Purge Valves: 2,000 - 10,000 psi

on-off valves
On/off and prime/purge valves
close move

Valco high pressure on/off or prime/purge valves feature quality engineering, precision machining, and extremely low internal volume (< 2 µl), making them the ideal choice in the most demanding liquid or supercritical fluid chromatography or extraction systems.*

The valve needle is made from a special high strength alloy which is resistant even to the buffer salts which might accidentally precipitate inside the valve. Seals are fluorocarbon, with valve bodies machined from HPLC grade stainless steel, ensuring long lifetime in even the most demanding situations.

The on/off function is self-explanatory; in prime/purge models, mobile phase flows around the needle when the valve is closed, relieving the back pressure from the column. When the valve opens, mobile phase vents to waste to prime the pump.

Standard models provide leak-tight operation up to 10,000 psi liquid (690 bar) at 100°C, with high temperature versions rated up to 6,000 psi liquid/300°C. A 1/16" fitting model with a larger bore and a 1/8" fitting model (rated at 2000 psi liquid) are available for high flow applications.

* Not suitable for use with gases

Temp range Actuation Fitting Bore Product No.
Standard Manual 1/16" 0.50 mm SFVO
0.75 mm SFVOL
Air actuated, 1" standoff 1/16" 0.50 mm ASFVO
0.75 mm ASFVOL
Manual 1/16" 0.50 mm SFVOHT
Manual, 4" standoff 1/16" 0.50 mm SFVOHT4
Air actuated, 2" standoff 1/16" 0.50 mm ASFVOHT
0.75 mm ASFVOLHT
1/8" 1.50 mm ASFVO2HT
Air actuated, 4" standoff 1/16" 0.50 mm ASFVOHT4
0.75 mm ASFVOLHT4
1/8" 1.50 mm ASFVO2HT4
Standard Manual 1/16" 0.50 mm SFV
0.75 mm SFVL
Air actuated, 1" standoff 1/16" 0.50 mm ASFV
0.75 mm ASFVL
Air actuated, 2" standoff 1/16" 0.50 mm ASFVHT
0.75 mm ASFVLHT
1/8" 1.50 mm ASFV2HT
Air actuated, 4" standoff 1/16" 0.50 mm ASFVHT4
0.75 mm ASFVLHT4
1/8" 1.50 mm ASFV2HT4


1/16" 100°C
10,000 psi liquid
High temperature
1/16" 300°C
6,000 psi liquid
1/8" 300°C
2,000 psi liquid




The air/CO2 actuated versions require a single three-way solenoid; application of 50 psi opens the valve; venting the air allows the spring to return the valve to the closed position.