Spunding question

[Dland]

Could a guy just put a lighter spring in the corny keg pressure relief valve and add say 5 oz of corn sugar to the keg? Just a random thought.

I do like the simplicity of a spunding valve on a gas in ball lock fitting. Does anyone sell those cheap?

Relief valve spring option likely hard to calibrate, plus may not seal up after desired pressure is released.

Attached is picture of two home made spunding valves. The one w tube is older manual version made w ball valve and plumbing parts.

 

[renstyle]

Could a guy just put a lighter spring in the corny keg pressure relief valve and add say 5 oz of corn sugar to the keg? Just a random thought.

I do like the simplicity of a spunding valve on a gas in ball lock fitting. Does anyone sell those cheap?

In a word, yes. They do make red 35psi and green 65psi replacements for the gray 100+psi PRV on corny kegs. Normally the reds are used with Fermzilla or Fermentasaurus kit as the vessel is rated max ~35psi.

Here's why I wouldn't recommend it:

In theory you could utilize one of the red PRV as a getcha-by spunder for a batch or two, but you won't have any fine control and it would be locked at 35psi. Blow off could become an issue preventing the PRV from seating properly once pressure opens.

For the money (easily a pair of tenners, max) you could have a DIY spunding valve with a nice guage.

 

[Gozie Boy]

Could a guy just put a lighter spring in the corny keg pressure relief valve and add say 5 oz of corn sugar to the keg? Just a random thought.

I do like the simplicity of a spunding valve on a gas in ball lock fitting. Does anyone sell those cheap?

PRVs are not to be used for regular operational purposes, but as your last safety resort for overpressuring. There is a tiny (but not zero) chance that routinely flowing head gas through a PRV could cause sticking issues in the valve which may (unknowingly) render it inoperative. Chances of a problem are low, but you don't need to go there so why do so when you can get a cheap spunding valve (BlowTie fitted to a gas QD) which also gives you much better pressure control?