What is Water Hammer? The noise from banging pipes is caused by shocks of high speed water flowing in the piping system when a fixture is suddenly closed. Sudden stoppage of the water (a noncompressible liquid) flowing at a given pressure and velocity causes a surge or spike of water and is called water hammer. When this occurs a pressure wave travels back through the piping until it finds a point of relief. Dishwashers, clothes washers, fast closing positive shutoff valves incorporated in the system, all contribute to creating water shock which is not only annoying but damaging to pipes and appliances. Watts Water Hammer Arrestors incorporate a permanent pre-charged sealed air chamber to absorb the shock. The sealed chamber prevents the loss of air to the water and ensures long and trouble-free life. All potential leak points are permanently sealed. Sizing and Placement
The fixture unit valve shown in the cold and hot water columns of Table A below are utilized in the sizing of water hammer arrestors. Once the total number of fixture units has been calculated for the hot and cold water branch lines serving a group of fixtures, this number can be applied to the sizing and selection Table B below to determine the appropriate size water hammer arrestor for the hot and cold branch lines. Table A -- Fixture Units Sizing Information
FIXTURE UNITS TYPE OF SUPPLY FIXTURE CONTROL TOTAL PUBLIC C.W. H.W. PRIVATE TOTAL C.W. H.W. Table B -- Series 15 Sizing and Selection
SIZE (DN) In. mm CROSS FIXTURE UNITS REF. PDI STANDARD Water Closet Water Closet Pedestal Urinal Stall or Wall Urinal Lavatory Bathtub Shower Head Bathroom Group Bathroom Group Separate Shower Service Sink Laundry Tubs (1-3) Combination Fixture Flush Valve Flush Tank Flush Valve Flush Tank Faucet Faucet Mixing Valve Flush Valve Closet Flush Tank Closet Mixing Valve Faucet Faucet Faucet 10 5 10 5 2 4 4 � � � 3 � � 10 5 10 5 11/2 2 2 � � � 3 � � � � � � 11/2 3 3 � � � 3 � � 6 3 � � 1 2 2 8 6 2 � 3 3 6 3 � � 1 11/2 1 8 6 1 � 3 3 � � � � 1 11/2 2 3 3 2 � 3 3 /2 /4 1 11/4 11/2 2
3 1 15 20 25 32 40 50 1-11 12-32 33-60 61-113 114-154 155-330 A B C D E F For additional information, send for ES-15. 2006 Plumbing Code Requirements
UPC-Uniform Plumbing Code
609.10 Water Hammer. All building water supply systems in which quick-acting valves are installed shall be provided with devices to absorb the hammer caused by high pressures resulting from the quick closing of these valves. These pressure-absorbing devices shall be approved mechanical devices. Water pressure-absorbing devices shall be installed as close as possible to quick-acting valves. IPC-International Plumbing Code
604.9 Water Hammer. The flow velocity of the water distribution system shall be controlled to reduce the possibility of water hammer. A water hammer arrestor shall be installed where quick-closing valves are utilized. Water hammer arrestors shall be installed in accordance with the manufacturer's specifications. Water hammer arrestors shall conform to ASSE 1010. 2 Series 05
For Light Commercial/Residential Systems
3 Model 05H-M1 /4" (20mm) Hose Type specially designed for in-line use with washing machines Features
� Economical and effective single fixture protection against water pressure shock � May be installed in concealed locations without access panels � Factory air charged and not rechargeable � May be installed in new or existing plumbing systems vertically, horizontally or at any angle 5 /8"05-C Pressure & Temperature
Operating Pressure: Designed especially for use in light commercial or residential applications on lines up to 150psi (10.55 bar) working pressure. Temperature Range: 33�F to 180�F (.6�C - 82�C) Air Preload: 60psi (4.22 bar) 3 /8" 05-CXT 5 /8" 05-CXT 3 /8" 05-PEX-T Models
05-C For compression installation on 1/2" CTS new or retrofit 05H-M1 For inline use with washing machines 05-C-T For either 1/4" icemaker or 3/8" lav supply tube installation 05-CXT For direct installation on supply stop either between stub out and stop or between stop and supply tube 05-PEX-T For either 3/8" or 1/2" inline PEX installation
For complete list of models, send for ES-05. Standards
Certified to ASSE 1010 and listed by IAPMO. Dimensions - Weight
Straight Models
MODEL SIZE (DN) in mm CONNECTION TYPE A in. mm in. DIMENSION B mm lbs. kgs. WEIGHT 05 05 05-CPVC 05-H 05H-M1 05-S 05-S 05-C 3 /8 1 /2 1 /2 3 /4 3 /4 1 /2 3 /4 5 /8 10 15 15 20 20 15 20 16 NPT NPT CPVC Hose Hose Sweat Sweat OD Comp. 51/4 51/2 411/16 63/8 611/16 51/2 47/8 55/8 133 140 118 162 170 140 124 143 11/4 11/4 11/8 2 33/16 1 1 11/4 32 32 29 50 81 25 25 32 0.34 0.36 0.10 0.48 0.60 0.30 0.08 0.40 0.15 0.16 0.05 0.20 0.27 0.14 0.04 0.18 B Tee Models
MODEL SIZE (DN) in mm CONNECTION TYPE A in. mm in. DIMENSION B mm lbs. kgs. WEIGHT 05-C-T 05-C-T 05-CXT 05-CXT 05-PEX-T 05-PEX-T 1 /4 3 /8 3 /8 5 /8 3 /8 1 /2 8 10 10 16 10 15 OD Comp. OD Comp. OD Comp. x Reverse Comp. Nut OD Comp. x Reverse Comp. Nut PEX PEX 413/16 413/16 413/16 413/16 411/16 411/16 122 122 122 122 119 119 23/4 3 213/16 31/16 21/4 21/4 70 77 72 78 58 58 0.17 0.17 0.17 0.18 0.12 0.12 0.07 0.07 0.07 0.08 0.05 0.05 A B 3 Series 150A
For Residential/Domestic Water Systems Only Features
� Pre-charged air chamber � Sealed in diaphragm � Rechargeable � Stainless steel chamber construction
Operating Pressure: Designed for residential/domestic water systems on lines up to 150psi (10.55 bar) working pressure. Temperature Range: 33�F to 180�F (.6C-82C) Maximum Velocity: 10 fps (.93 mps) Maximum Shock Pressure: 200psi (13.8 bar)
150A Models
MODEL DESCRIPTION in. SIZE mm CONNECTION TYPE 150A Water Hammer Arrestor Only 150A-HA Water Hammer Arrestor and Fitting 150HA Fitting Only 1 3 /2" /4" 3 /4" 15 20 20 NPT Hose Hose 150A-HA Dimensions
NOMINAL Pipe Size in. mm
1 LENGTH Pipe Up to ft. m psi 30 bar 2.11 psi 40 bar 2.81 psi 50 bar 3.52 FLOW PRESSURE - PSI and Number of 150A valves to install psi bar psi bar 60 4.22 70 4.92 psi 80 bar 5.62 psi 90 bar 6.33 psi bar 100 7.03 /2 15 3 /4 20 1 11/4 25 32 50 75 100 25 50 75 25 50 75 25 15.2 22.9 30.5 7.6 15.2 22.9 7.6 15.2 22.9 7.6 150A 150A 150A 150A 150A 150A 150A 2-150A 2-150A 2-150A � � � � � � � � -- � � � 2-150A � 2-150A � � � -- � � � � � � � � � -- � � 2-150A � � � -- 2-150A -- -- � � � � � � -- � -- -- -- 2-150A � -- 2-150A -- -- � -- -- -- � -- -- � -- -- -- -- -- -- For additional information, send for ES-150A. 4 Series 15
For Domestic/Commercial Systems Features
� NPT solid hex brass adapter for easy installation � May be installed in concealed locations without access panels and not rechargeable in the field � May be installed in new or existing plumbing systems with a standard pipe tee vertically, horizontally or at any angle � Factory air charged and permanently capped and solder sealed � Optional 15AK adapters available � Air pre-load is 60 psi (4.22 bar) � 15AK connects a 11/4", 11/2" or 2" (32, 40 or 50mm)
A Pressure -- Temperature
Operating Pressure: Designed to operate on all domestic and commercial lines @150psi (10.55 bar) working pressure. Temperature Range: 33�F to 180�F (.6�C to 82�C).
B Pre-charged Air Chamber Permanently Sealed from Water System Materials
Bodies: Hard drawn copper with custom internal mirror finish. Pistons, Threaded Adapter and Cap: Machined of free cutting brass. Seal: O-Rings, EPDM. Seal Lubricant: FDA approved for use in potable water systems.
NPT Solid Hex Brass Adapter for Easy Installation Standards
Listed by IAPMO, ASSE 1010 approved, ANSI A112.261M approved, PDI WH201 approved and certified. Dimensions -- Weight
MODEL SIZE (DN) NPT Connection in. mm A in. mm in. DIMENSIONS B mm lbs. kgs. WEIGHT 15 15 15 15 15 15 /2 3 /4 1 11/4 11/2 2 1 15 20 25 32 40 50 17/16 17/8 23/16 211/16 35/16 35/16 37 48 56 68 84 84 51/2 71/2 81/8 1013/16 111/2 147/8 140 191 207 275 292 378 .90 1.40 2.00 3.80 6.00 7.40 .41 .64 .91 1.72 2.72 3.36 5 Sizing and Placement
Water Hammer Arrestor Riser Rule 1 covers multiple fixture branch lines which do not exceed 20 feet length. Explanation - Fixture unit sizing and selection table is used to select the required PDI unit (water hammer arrestor).
Up to 20' Rule 1 Typical Branch Line
As shown above, it has been established that the preferred location for the water hammer arrestor is at the end of the branch line between the last two fixtures served. The location of the water hammer arrestor shown above applies to branch lines that do not exceed 20 feet in length, from the start of the horizontal branch line to the last fixture supply on this branch line. When the branch line exceeds the 20 foot length, an additional water hammer arrestor should be used. This practice is best defined by two rules which have been established to cover the placement of water hammer arrestors. Rule 2 covers multiple fixture branch lines which exceed 20 feet in length. Explanation - Fixture unit sizing and selection table is used to select the required PDI unit (water hammer arrestor). The sum of the fixture unit rating of units X and Y shall be equal to or greater than the demand of the branches.
Over 20' Rule 2 Selection for Long Piping Runs
The majority of sizing and selection applications will involve single and multiple fixture branch lines. These are easily handled with the sizing and selection table. The remainder of the applications involve individual runs of piping to a remote item of equipment. The properly sized water hammer arrestor for such applications can be determined by the tables below. Ideally, the flow pressure in branch lines serving fixtures should never exceed 55 psi. Pressure reducing valves should be installed to maintain proper pressure. When flow pressures are 65 to 85 psi the next size water hammer arrestor should be selected. Refer to sizing table for water pressure over 65 psi. All sizing data in this section is based on flow velocities of 10 fps or less. The certification testing was conducted with a velocity of 10 fps to offer assurance that PDI approved units were capable of handling shock of maximum intensity that may be encountered. When long runs of piping are employed to serve a remote item of equipment, the water hammer arrestor should be located as close as possible to the point of quick closure. At this location, the water hammer arrestor will control the developed energy and prevent the shock wave from surging through the piping system. A typical example of placement is as shown. Sizing Table
For Water Pressures up to 65psi
LENGTH OF PIPE
1 NOMINAL PIPE DIAMETER - IN. /2"
3 /4" 1" 11/4" 11/2" 2" 25 50 75 100 125 150 A A B C C D A B C D D E B C D E F F C D AE F AF DF D E F CF EF FF E F EF FF EFF FFF Over 65 psi and up to 85psi
LENGTH OF PIPE of Pipe
1 NOMINAL PIPE DIAMETER - IN. /2"
3 /4" 1" 11/4" 11/2" 2" 25 50 75 100 125 150 B B C D D E B C D E E F C D E F CF CF D E F CF DF FF E F CF EF FF DFF F CF FF EFF BFFF FFFF Water Hammer Arrestor Shock Quick Closure Valve Long Run of Piping
Outlet Water Safety & Flow Control Products USA: 815 Chestnut St., No. Andover, MA 01845-6098; www.watts.com Canada: 5435 North Service Rd., Burlington, ONT. L7L 5H7; www.wattscanada.ca F-WHA 0630 � Watts Regulator Company, 2006