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Max 1.0 MPaMax 90°CMaintenance-Free

Yoshitake WP-1 Water Hammer Arrester (Shock Killer)

Yoshitake WP-1 Shock Killer water hammer arrester. Features a compact brass body, 1.0 MPa max pressure, and maintenance-free operation for residential and commercial piping.

Yoshitake WP-1 Water Hammer Arrester (Shock Killer)

Yoshitake WP-1 Shock Killer water hammer arrester helps create a comfortable residential environment. Since complex housing and office buildings become higher and larger, the residential environment faces various threats, including noise caused by water hammer. Just a little carelessness can bring about damage to devices or disturbance of sleep. The WP-1 Shock Killer absorbs water hammer effectively and protects the piping system.

Yoshitake WP-1 water hammer arrester product appearance

Features

  1. Gently absorbs water hammer in buildings with high water pressure.
  2. Prevents water hammer at the operation of water faucet lever at toilet or wash basin.
  3. Slim and compact body permits horizontal or vertical piping.
  4. Prevents water hammer damage to piping and devices.
  5. Once installed, it can serve perpetually without maintenance.

Specifications

Nominal size15A20A25A
ApplicationCold and hot water, City waterCold and hot water, City waterCold and hot water, City water
Maximum pressure1.0 MPa1.0 MPa1.0 MPa
Maximum temperature90°C90°C90°C
Maximum flow velocity3 m/s3 m/s3 m/s
Material (Body)BrassBrassBrass
Material (Pipe)CopperCopperCopper
ConnectionJIS RJIS RJIS R
Charged pressure0.15 MPa0.15 MPa0.15 MPa

Dimensions and Weights

Nominal sizedH (mm)A (mm)B (mm)Weight (kg)
15AR 1/212328.3320.25
20AR 3/415428.3320.30
25AR 118234.8410.50

Yoshitake WP-1 dimensions and structural drawing

Effectiveness against Water Hammer

The figures below show the difference in water hammer level between when the Shock Killer is used and not used.

Fig. 1 When the Shock Killer is not usedYoshitake WP-1 water hammer level when the Shock Killer is not used

Fig. 2 When the Shock Killer is usedYoshitake WP-1 water hammer level when the Shock Killer is used

The Shock Killer is available mainly for the two applications below.

Application 1: General House and Complex Housing

How to Use and Select

  1. In principle, install one Shock Killer in each house.
  2. To select a nominal size, find the unit of load for each water supply device in Table-1 (under Private room). Apply it to Table-2, and find an appropriate nominal size of the Shock Killer.
  3. Install another Shock Killer to branch piping if the branch piping is more than 4 meters.
  4. Additionally, install the Shock Killer close to devices such as solenoid valves where water hammer is a serious problem.

Installation Position

  1. Install the Shock Killer midway between the end branch piping and the branch piping before it (in a position within 6 meters from a water supply device).
  2. When installing the Shock Killer to the branch piping, place it close to a water supply device. When two or more water supply devices are used, install it between the end water supply device and the water supply device before it.

Application 2: High-rise Buildings and Multipurpose Buildings

How to Use and Select

  1. Handle the water supply piping as separated on each water supply system.
  2. In principle, install one Shock Killer per 6 meters of branch piping.
  3. To select a nominal size, find the unit of load for each water supply device in Table-1 (under Public use). Apply it to Table-2, and find an appropriate nominal size of the Shock Killer.

Note on Large Loads

If the units of load in total is over 60, use a proper number of 25A Shock Killers to fulfill the units of load.

Installation Position

  1. Install the Shock Killer midway between the end water supply device and the water supply device before it.
  2. When installing two or more Shock Killers, install one midway between the end water supply device and the water supply device before it, and the others at equal intervals between the first Shock Killer and the water supply device on the start point.

Selection Tables

Table-1 Unit of load for water supply devices (Excerpted from SHASE Handbook)

Name of deviceFaucetUnit of load (Public use)Unit of load (Private room)
Toilet basinFlush valve106
Toilet basinFlush tank53
UrinalFlush valve5-
UrinalFlush tank3-
Wash basinWater faucet21
Hand wash basinWater faucet10.5
Medical wash basinWater faucet3-
Office sinkWater faucet3-
Kitchen sinkWater faucet-3
Cookery sinkWater faucet42
Cookery sinkMixing valve3-
Dishwashing sinkWater faucet5-
Multi-station sinkWater faucet-3
Vanity sink (per faucet)Water faucet2-
Scrab sinkWater faucet43
BathtubWater faucet42
ShowerMixing valve42
Bathroom-Modular bathEquipped with toilet basin with flush valve-8
Bathroom-Modular bathEquipped with toilet basin with flush tank-6
Drinking water fountainDrinking water faucet21
Water heaterBall tap2-
Sprinkler-garageWater faucet5-

Hot Water Tap Adjustment

When a hot water tap is also used, the unit of load for a water supply device to a tap shall be 3/4 of the appropriate value shown in the table above.

Table-2 Nominal size selection table

Total units of load for water supply devicesNominal size
1-1115A
12-3220A
33-6025A

Example of Installation

Yoshitake WP-1 example of installation in a piping system

Construction and Materials

Yoshitake WP-1 detailed parts and materials drawing

No.Name of PartsMaterialQ.TY
1BodyBrass (C3531)1
2PipeCopper (C1220)1
3PistonBrass (C3531)1
4O RingNBR2
5LabelPolyester1
6DiscNBR1
7LabelPolyester1

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