water butterfly valve
butterfly valve gas
3 way butterfly valve
Theoretically dropping high pressure across two valves is better than one valve. However, in practice, two valves will not usually control well together unless the process can operate with a very low proportional band with a slow response time. A better alternative is to use a valve with internal multiple pressure drops. THINKTANK™ manufacture multi-hole and labyrinth trim for such condition. This design reduces cavitation, excessive leakage, hazardous noise, vibration, and mechanical failures.
