Control Devices - VR25-100 VR Series Brass Vacuum Relief Valve, 0-30" Hg Vacuum Range, 1/4" Male NPT

I am using this with a yeast system that includes a silonide and regulator. This is used to prevent to much pressure developing in the yeast bottle. It functions perfectly. This system is far easier to adjust then any pressurized CO2 system. Along with the fishmate feeder I can take off for a couple of weeks vacation an be confident that my aquarium will self maintain.

Holds vacuum at a steady level but sometimes at certain levels of flow it will make a whistling sound. Simply turning it in one direction and then back usually stops the sound.

I run a commercial grade vacuum pump and this is my regulator essentially- works awesome. Great adjust ability.

I have an application with an electronic variable vacuum adjustment. I wanted something to use as a "fail safe" so that if the electronic regulator failed, it would still not pull more than a specified level of vacuum to avoid damage to the system. This gizmo fits the bill perfect. I was able to set it to just above the maximum vacuum the regulator is supposed to allow. If the regulator doesn't do it's job for whatever reason, the valve opens and prevents over (vacuum) pressurizing.Setting the pressure can be a bit fiddly, but as long as you don't need to be super precise it's easy enough to get it adjusted.

Just what I needed to regulate the level of vacuum. Would be nice if it had some sort of graduations on it (perhaps with similar markings as micrometers have) to indicate actual levels of vacuum, but it works well.

It's hard to find good Schrader valves with weak enough springs for water well service. These vacuum breakers are adjustable.

This piece was used to control the pressure of a vacuum system in the lab. It screws out quite a bit and the pressure varies almost linearly with the number of times turned.

This device seems well made and durable, but if you are intending to attach it to a beverage line or passing liquid near it that is intended for consumption, think twice. Having read about various factories mixing lead in their brass, I decided to buy a reliable lead testing kit and tested all my recent brass connector purchases. Six out of 20 items tested positive for lead content. This item was one with lead in it.