Dykhatelny valve pressure (GAS). it is filled or emptied.

Вакуумный клапан давления предназначен для поддержания атмосферного давления внутри бака, пока он заполняется или опорожняется.
When the tank is full, the valve allows air to escape, thus avoiding excess pressure inside the tank, which can cause the tank to expand and "swell".
When emptying, it equalizes the pressure inside the tank with the external pressure and protects the tank from collapse.
The vacuum valve is made of acid-resistant stainless steel AIISI 316L and is widely used in the food industry in the production of beverages and oil, winemaking, cosmetic and chemical production. Pressure breathing valve (GAS)

* Available sizes: 2 "- 2 ½"
* Easy disassembly
* Compact design(//tractor-service.com)
* BSP connection (step thread)
* AISI 316L stainless steel parts
* Spring AISI 302
* Sealing NBR
* Working pressure 1 bar
* Opening pressure (overpressure) 15 mbar
* Opening pressure (vacuum) 20 mbar
* The maximum working temperature is 60 ºC. They will help you place an order!