Transcript SRC4 BLOW
Drinking Water + Compressed Air = Dangerous Mixture “Winterizing Irrigation Systems” Spokane Regional Cross Connection Control Chapter Requirements for Winterizing Irrigation Systems with Compressed Air Winterizing Irrigation Systems With Compressed Air • Winterizing of irrigation systems is necessary in many areas of the U.S. • The days of using manual drains to winterize these systems is being replaced with compressors utilizing compressed air. (Some compressors equipped with oil injection for lubing tools) • If the procedures for using compressed air are done correctly and the potable system is properly protected, this method works quite well. • However we estimate less than 10% are doing this procedure correctly. • The backflow hazard ranges from a low to high hazard. • Water quality complaints escalate during the 2 ½ month Winterizing period. ( Difficult to document because most of the time positive proof is lacking) • Not only is this a danger to the potable water system, it costs the purveyors time and money (investigating, sampling, flushing, etc). Reasons For This Problem In Our Area • Lack of approved backflow protection (DCVA or RPBA) • Lack of enforcement of Local Administrative Authority (plumbing inspectors) • Lack of designated blow-out port correctly installed • UPC doesn’t address blow-out port • Lack of educated “Blowout Technician's” Therefore……. • SRC4 area water purveyors are requiring backflow protection and encouraging designated blow-out ports on new and existing irrigation systems • These purveyors have implemented an aggressive education program (training and brochures, including newspaper articles, irrigation/landscapers contractors, purveyors customers, BPA wholesalers/retailers/box stores, etc) How can we protect the potable water system from this potential backflow ? 1. Educate • Begin an education program similar to ours. 2. Require approved backflow protection • Backflow Prevention Assembly (BPA) must be designed for the hazard, backpressure, installed correctly, tested annually by a certified tester, repaired as necessary and written documentation all of the above. 3. Designated blow-out port downstream of BPA • A designated blow-out port or similar compressor connection must be installed downstream of BPA. There shall not be any means of connecting compressor upstream of BPA. 4. Winterizing BPA • Compressed air shall not be used to Winterize BPA (will cause damage). If assembly cannot be removed and stored in a warm place, assembly must be partially disassembled and drained. All ¼ turn ball valves shall be Winterized by leaving them in 1/8 open/close position. About The Diagrams The following diagrams are examples of the correct location of BPA and designated blow out port in a typical irrigation system. These diagrams do not include how the potable water is supplied to the irrigation BPA. The supply piping may be a designated irrigation supply tapped off a water main (in the street), tapped off the water service line to a home or business (downstream of the water meter), or tapped off the facilities' plumbing system inside the building. Wherever the supply to the system is tapped, it must be controlled with a shut off valve, Winterizing including from the tap to the BPA, the BPA and the irrigation system. The tap, method of draining the system, type of BPA, etc, must meet local Jurisdiction requirements (including a permit). Enclosed information is exerts from of a presentation by Denny Lopp [email protected] Approved Backflow Protection With Blow-out Port Installed Downstream of BPA Approved BPA with a Combination CV Body With Blowout Port - Compressor blow-out port is located downstream of BPA. - BPA must be drained (disassembled in some cases) in order to Winterize assembly. - This design protects the potable water system. Compressor is connected to the blow-out port (hosebibb, tee with a plug, etc). Compressed Air BLOWOUT PORT Potable Water* Approved BPA* Public Water Supply Irrigation System Flow * Approved BPA may be DCVA or Note: RPBA Supply and drain valves subject to (must meet local jurisdiction requirements) requirements of local jurisdiction. Meter To customer’s plumbing system Containment Program ends at property line (State Regulations) * Potable water supply connection to the irrigation system must meet local jurisdiction requirements and shall be tapped into the water service downstream of the meter in Administrator theLocal water service pipe line (outside or inside the Authority begins home/facility). (UPC) Approved BPA with Built In Unions and Optional Blow-out Port - Compressor can be connected to downstream union with BPA removed, or connected to blow-out port with BPA installed or removed. - This design protects the potable water system. - BPA can be removed for Winterizing or drained and reinstalled. Step #1 Blowout port RPBA or DCVA Potable Water Irrigation System SOV #2 SOV #1 Unions Compressor Step #2 Potable Water Irrigation System Flow Approved BPA Installed With Unions and Optional Blow-out Port - Compressor can be connected to downstream union with BPA removed, or connect compressor to blow-out port with BPA installed. - This design protects the potable water system. - BPA can be removed for Winterizing or drained and reinstalled. Step #1 Blowout port RPBA or DCVA Potable Water Irrigation System Unions Flow Step #2 Potable Water Unions Flow Irrigation System Approved BPA With Blow-out Adapter - Center section of assembly can be removed and blow-out adapter installed in assembly body. - Compressor is connected to the adapter and blows out system. - Center section of assembly (both CVs and relief valve if so equipped) can be stored in a warm place. - This design protects the potable water system. Step #1 Compressor Flow Potable Water BPA with blowout adapter Irrigation System Step #2 Compressed Air Potable Water BPA with blowout adapter Irrigation System Approved Backflow Protection With Blow-out Port Installed Downstream of BPA Approved BPA with a Combination CV Body With Blowout Port - Compressor is connected to the blow-out port. - BPA must be drained (disassembled in some cases) in order to Winterize assembly - This design protects the potable water system Compressor is connected to the blow-out port (hosebibb, tee with a plug, etc). Compressed Air BLOWOUT PORT Potable Water* RPBA or DCVA Irrigation System Flow Public Water Supply Note: Supply and drain valves subject to requirements of local jurisdiction. Meter To customer’s plumbing system Containment Program ends at property line (State Regulations) * Potable water supply connection to the irrigation system must meet local jurisdiction requirements and shall be tapped into the water service downstream of the meter in Administrator theLocal water service pipe line (outside or inside the Authority begins home/facility). (UPC)