1 Pressure Reducing valves

2

3 Fill Valve / PRV Pressure Reducing Valve

4 Pressure Reducing Valve Establish cold fill pressure. Check valve. Strainer Valve

5 Pressure Reducing Valve LOCATION WHAT SETTING

6 Why Here Most stable location in The hydronic system

7 WHAT SETTING

8 Pressure Reducing Valve PRV FAN COIL BOILER What Pressure setting? Fill piping so top of system has 4 or 5psi

9 Pressure and Head Equivalence Or: psi / Ft. For reference, complete equation: Head (ft) = head (psi) x 2.31 specific gravity

10 Pressure Reducing Valve 4 STORY BLDG. 60 FT HIGH 2.31 FT = 1 PSI MINIMUM 5 PSI AT TOP OF BUILDING PRV FAN COIL BOILER

11 Pressure Reducing Valve 4 STORY BLDG. 60 FT HIGH 2.31 FT = 1 PSI 60’ height is equal to _____ psi static press PRV FAN COIL BOILER 5psi

12 Pressure Reducing Valve 4 STORY BLDG. 60 FT HIGH 2.31 FT = 1 PSI 60’ height is equal to 26psi static press Set to 5psi + 26psi PRV: 30 or 31psi setting FAN COIL BOILER 5psi

13 Pressure Reducing Valve 4 STORY BLDG. 60 FT HIGH 2.31 FT = 1 PSI MINIMUM 5 PSI AT TOP OF BUILDING PRV BOILER FAN COIL

14 Pressure Reducing Valve 4 STORY BLDG. 60 FT HIGH 2.31 FT = 1 PSI MINIMUM 5 PSI AT TOP OF BUILDING PRV 5psi BOILER FAN COIL

15 Pressure Reducing Valve 4 STORY BLDG. 60 FT HIGH 2.31 FT = 1 PSI Pressure at bottom if set at 20psi at top? PRV 20psi BOILER FAN COIL

16 Pressure Reducing Valve 4 STORY BLDG. 60 FT HIGH 2.31 FT = 1 PSI Pressure at bottom if set at 20psi at top? 20psi + 26psi = 46psi PRV 20psi BOILER FAN COIL

17 4 feet 5 feet 10 feet 19 ft / 2.31 ft/psi = 8 psi 8 psi + 4 psi = 12 psi “Cold Fill” or Initial Pressure

18 System Relief Valve Limits maximum system pressure. ASME Code – Section IV –Capacity (BTU’s/Hr) –Pressure relief setting (PSI)

19 The “pressure band” u Upper pressure limit, P 2 u Relief valve setting u Lower pressure limit, P 1 u PRV setting Allowable pressure rise