Virginia Graeme Baker Pool & Spa Safety Act
FBC Section R4101.6.6
As of March 1, 2009, the Building Department will require basic compliance with the Pool & Spa Safety Act for drain covers, flow, and pipe sizing through dual or multiple drains in accordance with the ANSI/APSP-7 2006, Standard for suction entrapment avoidance in swimming pools, wading pools, spas, hot tubs, and catch basins.
BASIC REQUIREMENTS FOR FLOW & PIPE SIZING:
Maximum flow through branch piping shall be limited to 6 feet per second velocity. Branch piping is the piping between the drains (**the trunk line piping from the “tee” between the drains to the pump is NOT branch piping.**)
To comply with this requirement the builder must:
- Specify the maximum system flow rate in gallons per minute (gpm).
- Specify the size of the branch piping which will allow the maximum system flow to move through the branch piping at no more than 6 feet per second(fps)velocity.
- Validate the specified flow rate by using one of the three prescribed methods in the Standard and specify the pump make and model which will deliver this flow rate.
If the contractor has complied with the three steps above, he is in compliance with the code requirements detailed in the standard.
According to the standard, the flow rate validation required in step 3 above may be achieved by either:
NEW REQUUIREMENTS FOR DRAIN COVERS/GRATES:
- Calculating total dynamic head (TDH): The sum of all resistances in a complete operating system (pipe, fittings, valves, filter, heater, etc.)
- Performing a simplified TDH calculation: A method of determining the maximum system flow rate using hydraulic calculations based on the lowest possible total dynamic head (TDH) for a circulation system. For example, calculate pipe resistance using the shortest distance between the pool and the pump, omitting the calculations for fittings/valves, and using the best performance ratings for filters and heaters
- Using the maximum flow capacity of the pump (this will be shown on the pump performance curve provided by the manufacturer.
Suction outlet covers/grates shall be tested and listed by a nationally recognized testing laboratory as conforming to the most recent edition of ASME/ANSI A112.19.8-2007 and include a permanently marked flow rating tested to prevent hair entrapment.
For dual drains the flow rating for each listed cover/grate shall be greater than the maximum system flow. For systems with more than two drains per pump, refer to the standard.