How are pressure-reducing devices treated in NFPA 20 discharge systems?

How are pressure-reducing devices treated in NFPA 20 discharge systems?

• A. They may be used to limit downstream pressure, but must be properly installed and tested to avoid performance loss
• B. They must never be used in NFPA 20
• C. They always operate without testing
• D. They should be installed only on the suction side

Answer: (A)

Pressure-reducing devices can be used on NFPA 20 discharge systems to limit how much pressure appears downstream, protecting piping, fittings, and sprinklers from excessive pressure. They are placed on the discharge side of the pump so the system only sees the set reduced pressure and the pump operates within the intended hydraulics. The key is that they must be properly installed and tested. If a pressure-reducing device is mis-set or installed without proper review, it can cause inadequate pressure at the farthest sprinklers or other performance issues, undermining the system’s reliability. Thorough installation and acceptance testing verify that the pump can still meet the required pressures and flows under design and actual operating conditions. It’s not correct to say they can’t be used, or that they require no testing, or that they belong on the suction side.

Pressure-reducing devices can be used on NFPA 20 discharge systems to limit how much pressure appears downstream, protecting piping, fittings, and sprinklers from excessive pressure. They are placed on the discharge side of the pump so the system only sees the set reduced pressure and the pump operates within the intended hydraulics.

The key is that they must be properly installed and tested. If a pressure-reducing device is mis-set or installed without proper review, it can cause inadequate pressure at the farthest sprinklers or other performance issues, undermining the system’s reliability. Thorough installation and acceptance testing verify that the pump can still meet the required pressures and flows under design and actual operating conditions.

It’s not correct to say they can’t be used, or that they require no testing, or that they belong on the suction side.