The Auto Air Valve (aka Gatekeeper) is the recommended control valve for a pressure-hold blasting system.  It is safer and superior to a pinch valve system.  Further details as follows:

• Rugged, compact design
• Typically used in conjunction with the Thompson Valve
• Low pressure drop across valve – increases production
• Multiple sizes available.
• Retrofit systems are available to convert pinch valve / donut valve systems to safer and more efficient Auto Air valve systems – see options below.