From the product description, check product page for current description, price and availability:

With this complete kit you’ll be ready to use the BlowTie Spunding Valve right out of the box. The BlowTie is used to release excess pressure on a pressurized fermenter or from a receiving keg during pressure transfers. This diaphragm spunding valve is much more accurate than the spring and poppet style, and works much better at lower pressures.

Pressure Fermentation
Pressure fermentation is becoming more and more popular at the homebrew level, but in order to do it safely and accurately, you need a way to release excess pressure. You’ll pressurize your vessel to your desired psi, but once fermentation begins and those hungry, active yeast start creating CO2, the pressure inside the vessel will increase. Attach a spunding valve and set it to your desired pressure, and it will blow off when the pressure gets to high and close up again when it’s back to your desired psi.

Pressure Transfers
Even if you don’t have a pressurizable fermenter, you may have done pressure transfers from keg to keg during filtering or after fining. During pressure transfers, it’s a good idea to have a bit of head pressure in the receiving keg, especially if you’re transferring beer that is already carbonated. Having a spunding valve in place will allow you to consistently control the head pressure and give you more consistent results, without losing carbonation in the process.

Diaphragm vs. Poppet
With the poppet style spunding valve, a spring pushes against a poppet to keep the valve closed. When the poppet lifts up to open, the surface area the gas pushes against becomes larger, and the spring has to work harder to push the poppet down and reseal the valve. This can lead to more gas being released than intended, and the remaining pressure in your vessel may be at a lower psi than your spunding valve’s set psi.

Instead of a poppet, the spring inside the BlowTie pushes against a diaphragm, which has an immensely larger surface area. This means the surface area that the gas pushes against while the diaphragm is closed is significantly closer to the surface area it pushes against when the diaphragm is open. This leads to higher accuracy, and the remaining pressure after excess gas is released will be much closer to your set blow off pressure.

Kit Includes:

• BlowTie
• Pressure Gauge
• Ball Lock Disconnect
• Duotight Tee & Flared Duotight Fitting
• 2x Lengths of EVABarrier 8mm OD Tubing

From the product description, check product page for current description, price and availability:

A spunding valve is a great accessory to have when performing pressure transfers and is a must-have for fermenting under pressure. Designed by the MoreBeer! R&D team and made from stainless steel components for long-lasting quality. Our spunding valve features the Torpedo Keg gas-in disconnect and our specially designed adjustable stainless gas pressure relief valve (D1833L). This model also features a pressure gauge that reads from 0-15 psi.

Don’t need the gauge? Check out our FIL42S.

Pressure Fermentation
Pressure fermentation is becoming more and more popular at the homebrew level, but in order to do it safely and accurately, you need a way to release excess pressure. You’ll pressurize your vessel to your desired psi, but once fermentation begins and those hungry, active yeast start creating CO2, the pressure inside the vessel will increase. Attach a spunding valve and set it to your desired pressure, and it will blow off when the pressure gets to high and close up again when it’s back to your desired psi.

Pressure Transfers
Even if you don’t have a pressurizable fermenter, you may have done pressure transfers from keg to keg during filtering or after fining. During pressure transfers, it’s a good idea to have a bit of head pressure in the receiving keg, especially if you’re transferring beer that is already carbonated. Having a spunding valve in place will allow you to consistently control the head pressure and give you more consistent results, without losing carbonation in the process.

Note: The very end of the pressure relief valve can be adjusted by unscrewing the knurled adjustment knob. If too tight and not adjustable by hand, wrap a towel around the adjustment knob and loosen with pliers. Then finger tighten or loosen to desired pressure.