This kit has been designed for simplicity and ease of putting together. 
 
If you want to control the pressure retained in a pressure vessel that is releasing pressure then the BlowTie Diaphram Spunding Valve is the tool for the job.
 
The adjustment knob on the top of the unit makes it easy to increase and decrease the set pressure.
 
This BlowTie unit can be easily dissassembled for cleaning using a phillips head screw driver.
 
Designed to suit 8mm (5/16") Evabarrier Tubing.  It's compatible with both the 4mm ID Tubing here or 5mm ID here.
 
Specifications:
1. Suits pressures 0-15psi (but with different guages the unit can go above 100psi)
2. Made from food grade acetal
3. Stainless screws
4. 8mm (5/16") push on both sides