Reduced Pressure Zone Valves
Part Number: BA
Mechanical backflow preventers approved for protection against backpressure and backsiphonage for Fluid Categories 1 – 4. RPZ Valves (BA devices) are acceptable to all water companies in the U.K. - when installed and used in accordance with the Water Regulations.
RPZ Option F (model BAF) features a large capacity fine strainer ensuring reliable operation.
• Brackets (BRA) - Provide correct rear clearance as required by AIM 08-01 Issue 1. Sizes 15 - 108 mm
• Cabinet - Grey, uninsulated (BACAB2) - Supplied as an assembly, housing the RPZ. Very compact (300x300x200) - Suitable for 15 or 22 mm, option A or B assy.
Where indicated on the drawing, a Reduced Pressure Zone assembly shall be installed – model BA - as manufactured and commissioned by Arrow Valves Ltd - Tel 01442 823123. The installation shall comply with AIM 08-01 Issue 1 as available on the manufacturer’s web site. Full bore servicing valves shall be provided either side of the device. A fine strainer1 and a non-return valve shall be provided upstream of the RPZ valve to minimise discharge. The base of the valve must be 300 – 1500 mm above the floor and adequate access shall be provided for testing with a minimum 150 mm clearance above the valve2. When installed in a Plant Room or similar tamperproof environment, the valve assembly shall be supported with proper brackets with the correct rear clearance. In other situations the assembly shall be housed in the manufacturer’s cabinet. A discharge pipe must be connected to the tundish and taken to a gully. Where the discharge is to be taken into a waste pipe, a waterless trap shall be used. The assembly must be commissioned prior to use in accordance with the Water Regulations.
Insert as required:
 shall have a 100 micron mesh and self clean at weekly intervals by means of an electrical actuator
 When used for filling a heating system, the assembly shall include a Pressure Reducing Valve.
Many applications that are Fluid Category 3 in a house, become Category 4 in non-house (commercial) situations. Subjective applications (e.g. hose union taps) are to be “risk assessed” by water supplier. Category 4 examples include -
• Quick fill heating systems non-house >45 KW (see Autofill)
• Hose union taps – commercial, not cat. 5. (see SPBA)
• Clothes washing machines - commercial use, not cat. 5
• Dishwashers - commercial use, not cat. 5
• Sealed heating systems - non-house >45 KW (see Autofill)
• Chilled water circuits and run around coils (see Autofill)
• Storage cisterns - without suitable air gap
• Mini-irrigation systems with porous hoses
• Wash-down hoses – not fluid category 5
• Water treatment plant – commercial
• Vehicle washing plant / degreasing
• Water softening – non ion exchange
• Fire sprinklers with anti-freeze solutions
• Food processing
• Bottle washing
• Brewery & distillation plant
• Refrigerating equipment
• Cooling water / foundries
• Printing / photographic equipment
• Carcinogenic substances / chemicals
• Pesticides / insecticides / herbicides
• Any application approved by water supplier
• 'RPZ Valves Uncovered' - 'Plumbing' Magazine article by Arrow Valves' Technical Director