INSTRUM® Breather valves

INSTRUM® is working successfully world-wide for more than 30 years in the development, construction and manufacturing of pressure regulators for tank blanketing and inerting. INSTRUM® pressure regulators can be generally used in liquids and gases, particularly in corrosion-proof applications.

  • Nominal pipe sizes DN15..100 /ANSI ½“..4“
  • Opening pressure 2..100 mbar/0,03..1,5 psi
  • Positive or negative pressure
  • Stainless steel or PTFE
  • Temperature range -190 to +200°C
  • Kv-values range between 6..1440


In process tanks under certain conditions further safety measures can become necessary. Whenever pressure in the tank can increase or decrease a limit, which can be critical for the design of the tank (when operating conditions in the tank are beyond the permissible positive pressure or vacuum limit) the operator must take care to avoid these conditions. Usually burst disks are used, but they have two disadvantages: First of all they can be used only once, second tank remains open when the disk broke and became destroyed. The main advantage of a check valve is, that the tank is getting closed again as soon as pressure will decrease the acceptable limit.

INSTRUM® offers systems with particularly spring-tensioned check valves type CD and CS, which will react in all nominal size ranges starting from 2 mbar. There are check valves available for highly corrosive applications, which use PTFE-GRP product-affected.
The installation position can be selected usually in accordance with the requirements of the application.


  • Check valves for positive pressure
  • Check valves for negative pressure, vacuum breaker
  • Backflow preventer
  • System separator