PS
Mechanical
- May 16, 2017
- 56
Hi Professionals,
I'm having few troubles in understanding the functioning of balancing valves.
Balancing valves are used to balance the flow among the load per design. We use static (manual) balancing valves in constant flow applications.
But, when it comes to the usage of dynamic (automatic) balancing valves, it is said that the valve will maintain constant flow under varying pressure conditions. I'm struck up here with the question: varying inlet pressure or varying downstream pressure or varying differential pressure across the valve?
If these valves are going maintain the SET flow (50 GPM, say) at all times, what will happen when the 2-way control valve is 50% opened? Will the balancing valve in the system try to maintain 50 GPM? If so, the purpose of 2-way valve becomes void. If NOT, the statement "the valve will maintain constant flow under varying pressure conditions" will contradict the actual function.
Now, recently we are using PIBCVs in hydronic piping. I have read that PIBCVs solve the purpose of both control and balancing in a single fit. Even here, I had a doubt that if the demand is 50%, what will be the flow across the valve? My guess, in case of PIBCVs, was there should be some setting in the control port that orders the balancing port that at 50% demand the balancing port should allow 50% (apprx) of SET flow rate. Am I right?
Please do help gaining more understanding about their usages. Also, please do suggest few articles explaining the purpose of each type of valves.
Thanks in advance for the suggestions.
I'm having few troubles in understanding the functioning of balancing valves.
Balancing valves are used to balance the flow among the load per design. We use static (manual) balancing valves in constant flow applications.
But, when it comes to the usage of dynamic (automatic) balancing valves, it is said that the valve will maintain constant flow under varying pressure conditions. I'm struck up here with the question: varying inlet pressure or varying downstream pressure or varying differential pressure across the valve?
If these valves are going maintain the SET flow (50 GPM, say) at all times, what will happen when the 2-way control valve is 50% opened? Will the balancing valve in the system try to maintain 50 GPM? If so, the purpose of 2-way valve becomes void. If NOT, the statement "the valve will maintain constant flow under varying pressure conditions" will contradict the actual function.
Now, recently we are using PIBCVs in hydronic piping. I have read that PIBCVs solve the purpose of both control and balancing in a single fit. Even here, I had a doubt that if the demand is 50%, what will be the flow across the valve? My guess, in case of PIBCVs, was there should be some setting in the control port that orders the balancing port that at 50% demand the balancing port should allow 50% (apprx) of SET flow rate. Am I right?
Please do help gaining more understanding about their usages. Also, please do suggest few articles explaining the purpose of each type of valves.
Thanks in advance for the suggestions.