EG
Civil/Environmental
- Mar 5, 2002
- 20
Hey all,
I am looking to expand my knowledge regarding how specifically a mainline prv functions and to gain some understanding of any particular nuances associated with them. We are located in a relatively remote mountainous area with limited, experienced people.
My eagerness stems from frustrations involving a particular in-fill development project that met all applicable fire flow requirements and operating pressures. However, an existing, adjacent multi-family project supposedly had insufficient operating pressures (how low? the utility department could not tell me). This adjacent project is at the upper limit of a pressure zone and we were directed to extend a mainline connection to their internal waterline from our site. This little request (actually our project would have been denied had we declined) cost us, not only a healthy sum of construction cost, but also a building due to the easement restrictions and swath of land the water line ate up.
Now, the most frustrating part is the adjacent property has a mainline extension stubbed to their site from the next higher pressure zone and stops short 5-feet from where they want us to extend our line to (by extending our line, the local water network would be all fed off the same pressure zone). I recommendended that instead of us extending a line all the way up to their site, why not simply install a PRV at the available junction between the 2 pressure zones. The utility department said that this would only benefit the system in the case of a fireflow event and would not help the multi-family project's consumers with their domestic pressure needs. I had replied that improving a fire flow event would indeed be a benefit to the system, however they were trying to alleviate some complaints from the adjacent property's tenants.
My simple understanding of a PRV is that it simply delivers the outlet pressure at a preset (lower) pressure by absorbing/consuming some of the energy from the higher pressure side. If that were true, why couldn't the system be setup to deliver the lower side at a pressure that would benefit the lower pressure zone users for their domestic use? Any help would be appreciated. Oh yeah, the utility department would only answer, "because we said so" OR "I can't show you why, we don't know how to run the model" <- believe it or not!
I am looking to expand my knowledge regarding how specifically a mainline prv functions and to gain some understanding of any particular nuances associated with them. We are located in a relatively remote mountainous area with limited, experienced people.
My eagerness stems from frustrations involving a particular in-fill development project that met all applicable fire flow requirements and operating pressures. However, an existing, adjacent multi-family project supposedly had insufficient operating pressures (how low? the utility department could not tell me). This adjacent project is at the upper limit of a pressure zone and we were directed to extend a mainline connection to their internal waterline from our site. This little request (actually our project would have been denied had we declined) cost us, not only a healthy sum of construction cost, but also a building due to the easement restrictions and swath of land the water line ate up.
Now, the most frustrating part is the adjacent property has a mainline extension stubbed to their site from the next higher pressure zone and stops short 5-feet from where they want us to extend our line to (by extending our line, the local water network would be all fed off the same pressure zone). I recommendended that instead of us extending a line all the way up to their site, why not simply install a PRV at the available junction between the 2 pressure zones. The utility department said that this would only benefit the system in the case of a fireflow event and would not help the multi-family project's consumers with their domestic pressure needs. I had replied that improving a fire flow event would indeed be a benefit to the system, however they were trying to alleviate some complaints from the adjacent property's tenants.
My simple understanding of a PRV is that it simply delivers the outlet pressure at a preset (lower) pressure by absorbing/consuming some of the energy from the higher pressure side. If that were true, why couldn't the system be setup to deliver the lower side at a pressure that would benefit the lower pressure zone users for their domestic use? Any help would be appreciated. Oh yeah, the utility department would only answer, "because we said so" OR "I can't show you why, we don't know how to run the model" <- believe it or not!