FNW 4707263 Commercial Water Hammer Arrestor Instruction Manual

FNW 4707263 Commercial Water Hammer Arrestor

Product Specifications

• Product Name: 10P/11P/X10P/X11P Water Hammer Arrestors
• Standard: PDI-WH 201, revision 1992
• Flow Velocity Limit: 10 FPS
• Maximum Branch Line Pressure: 55 PSIG
• Branch Line Pressure for Next Size Arrestor: >65 PSIG

Product Usage Instructions

Storage

If not used immediately, store the water hammer arrestors by:

1. Protecting threaded or sweat ends from damage.
2. Safeguarding against humidity, moisture, dust, dirt, and corrosive environments.

Sizing

Single and Multiple Fixture Branch Runs 20 ft And Shorter

1. Determine total fixture-units from Table 1 based on plumbing fixtures.
2. Select the correct size water hammer arrestor from Table 2 rounding up fractional fixture-units.

Example 1

• Cold Water Branch: 26 fixture-units – Select P.D.I. B Unit
• Hot Water Branch: 6 fixture-units – Select P.D.I. A Unit

Multiple Fixture Branch Runs Over 20 ft

1. Determine total fixture-units from Table 1 based on plumbing fixtures.
2. Select two water hammer arrestors whose total fixture-unit ratings meet or exceed the demand on the branch.

Example 2

• Cold Water Branch: 52 fixture-units – Select Two P.D.I. B Units
• Hot Water Branch: 12 fixture-units – Select Two P.D.I. A Units

Long Piping Runs (25 ft to 150 ft) To Remove Equipment

1. Select appropriate water hammer arrestor from Table 3 for branch line pressures under 65 PSIG.
2. Select appropriate water hammer arrestor from Table 4 for branch line pressures between 65 PSIG and 85 PSIG.

Frequently Asked Questions

• Q: Can the water hammer arrestor be modified?
  • A: No, modifying the water hammer arrestor voids the warranty and may compromise safety.
• Q: What should be done if branch pressures exceed 65 PSIG?
  • A: In such cases, it is recommended to use the next larger size water hammer arrestor to ensure proper functionality.

INTRODUCTION

This instruction manual includes sizing and installation information for FNW water hammer arrestors. The detail presented here is interpreted from The Plumbing and Drainage Institute’s Water Hammer Arrestors Standard PDI-WH 201, revision 1992. It is recommended that this document be reviewed for further sizing, placement and reference data on water hammer arrestors.

CAUTION

1. Verify that the application does not exceed the pressure or temperature rating of the water hammer arrestor.
2. To ensure safety and to maintain warranty, never modify the water hammer arrestor in any way.
3. Always verify installation, sizing and use requirements with local plumbing codes.

STORAGE

If the water hammer arrestors will not be used immediately, the following precautions should be taken:

1. Storage should include protection for threaded or sweat ends so that they are not damaged prior to use.
2. Water hammer arrestors should be protected to safeguard against humidity, moisture, dust, dirt, sand, mud, salt spray, sea water or other forms of corrosive and erosive environments.

SIZING

Sizing recommendations are based on an average flow velocity not exceeding 10 FPS. Ideally, the line pressure in a branch should not exceed 55 PSIG. To maintain proper branch pressure, a water pressure reducing valve should be installed. If, however, branch pressures exceed 65 PSIG, the next larger size water hammer arrestor is recommended.

Single and Multiple Fixture Branch Runs 20 ft And Shorter

1. Review the number and type of plumbing fixtures to be protected on a given branch.
2. Using Table 1, determine the total number of fixture-units required by that branch. Note that there may be varying fixtureunit weights depending on whether the branch is a hot water (H.W.) or cold water (C.W.) supply. In addition, be sure to select the correct application type, either Public or Private Use.
3. Use the total fixture-units to determine the correct size water hammer arrestor in Table 2. In the case of fractional fixture-units, always round up to the nearest whole number.

EXAMPLE 1

Cold Water Branch

• 2 Flush Valve Water Closets at 10 F.U. ea. 20
• 4 Lavatories at 1-1/2 F.U. ea. 6
• Total C.W. Branch Fixture Units 26

Select P.D.I. “B” Unit

Hot Water Branch

• 4 Lavatories at 1-1/2 F.U. ea 6
• Total H.W. Branch Fixture-Units 6

Select P.D.I. “A” Unit

Multiple Fixture Branch Runs Over 20 ft

1. Use the same procedures as above to determine the total fixture units for a given branch using Table 1.
2. Select two water hammer arrestors from Table 2 whose fixture unit ratings, when added, are equal to or greater than the demand on the branch. In the case of fractional fixture units, always round up to the nearest whole number.

EXAMPLE 2

Cold Water Branch

• 4 Flush Valve Water Closets at 10 F.U. ea 40
• 8 Lavatories at 1-1/2 F.U. ea. 12
• Total C.W. Branch Fixture Units 52

Select Two P.D.I. “B” Units

Hot Water Branch

• 8 Lavatories at 1-1/2 F.U. ea. 12
• Total H.W. Branch Fixture-Units 12

Select Two P.D.I. “A” Units

Long Piping Runs (25 ft to 150 ft)

To Remove Equipment

1. For branch line pressures under 65 PSIG, select the appropriate water hammer arrestor from Table 3 based on the nominal pipe size and overall length of pipe to the quick shut-off device.
2. For branch line pressures between 65 PSIG and 85 PSIG, select the appropriate water hammer arrestor from Table 4 based on the nominal pipe size and overall length of pipe to the quick shut-off device

TABLE 1

Fixture

|

Type of Supply Control

| Weight in Fixture-Units
---|---|---
Public| Private
Total| C.W.| H.W.| Total| C.W.| H.W.
Water Closet| Flush Valve| 10| 10| –| 6| 6| –
Water Closet| Flush Tank| 5| 5| –| 3| 3| –
Pedestal Urinal| Flush Valve| 10| 10| –| –| –| –
Stall or Water Urinal| Flush Valve| 5| 5| –| –| –| –
Stall or Water Urinal| Flush Tank| 3| 3| –| –| –| –
Lavatory| Faucet| 2| 1-1/2| 1-1/2| 1| 1| 1
Bathtub| Faucet| 4| 2| 3| 2| 1-1/2| 1-1/2
Shower Head| Mixing Valve| 4| 2| 3| 2| 1| 2
Bathroom Group| Flush Valve Closet| –| –| –| 8| 8| 3
Bathroom| Flush Tank Closet| –| –| –| 6| 6| 3
Separate Shower| Mixing Valve| –| –| –| 2| 1| 2
Service Sink| Faucet| 3| 3| 3| –| –| –
Laundry Tubs (1-3)| Faucet| –| –| –| 3| 3| 3
Combination Fixture| Faucet| –| –| –| 3| 3| 3

TABLE 2

FNW Size

| PDI Size Code| PDI Fixture Units
---|---|---
10P| 11P
1/2″| A| A| 1 to 11
3/4″| B| B| 12 to 32
1″| C| C| 33 to 60
1-1/4″| D| D| 61 to 113
1-1/2″| E| –| 114 to 154
2″| F| –| 155 to 330

EXAMPLE 3

A 2″ pipe leads from the main to a process tank that is isolated by a quick closing valve. The overall pipe run to the valve is 98 feet. The line pressure is 60 PSIG and the velocity is 10 FPS. According to Table 3, two P.D.I “F” units should be installed. Had the line pressure been 70 PSIG, two P.D.I. “F” units and one P.D.I. “E” units should have been selected.

TABLE 3

TABLE 4

INSTALLATION

Placement:

Water hammer arrestors should be placed as close to the source of shock as possible. Both hot and cold water branches should have arrestors. There should be an unobstructed path from the shock source to the water hammer arrestor. In figure 1, two shock waves are allowed at points A and B. Figure 2 shows the proper vertical installation, and figure 3 shows the proper horizontal installation. Water hammer arrestors should not be installed in the inverted position. In multiple fixture lines, the water hammer arrestor should be installed between the last two fixtures of the branch (as in example 1). On multiple fixture lines requiring two arrestors, one unit should be installed at the mid position of the branch, and the second arrestor should be installed between the last two fixtures of the branch (as in example 2).

LIMITED WARRANTY

Warranty

Subject to the limitations expressed herein, Seller warrants that products manufactured by Seller shall be free from defects in design, material and workmanship under normal use for a period of one year from installation but in no case shall the warranty period extend longer than eighteen months from the date of sale. This warranty is void for any damage caused by misuse, abuse, neglect, acts of God or improper installation. For the purpose of this section, “Normal Use” means in strict accordance with the installation, operation and maintenance manual. The warranty for all other products is provided by the original equipment manufacturer.

Claim Process and Remedies

Seller shall repair or replace, at its option, any non-conforming or otherwise defective product, upon receipt of notice from Buyer during the Manufacturer’s warranty period at no additional charge. SELLER HEREBY DISCLAIMS ALL OTHER EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS OR FITNESS FOR A PARTICULAR PURPOSE. In order to file a claim under the terms of this Warranty, a claimant must promptly notify FNW that a Product may be defective within 30 days of the suspected failure or defect via the telephone number, mail or website listed below and may be required to submit proof of purchase and/or photographs.

• Telephone: 1-800-221-3379
• Mailing Address: 751 Lakefront Commons, Newport News, VA 23606
• Website: fnw.com

All products alleged to be defective must be sent to FNW for inspection and testing for determination of the cause of the alleged defect or failure.

Limitation of Liability

UNDER NO CIRCUMSTANCES SHALL EITHER PARTY BE LIABLE TO THE OTHER FOR INCIDENTAL, PUNITIVE, SPECIAL OR CONSEQUENTIAL DAMAGES OF ANY KIND. BUYER HEREBY ACKNOWLEDGES AND AGREES THAT UNDER NO CIRCUMSTANCES, AND IN NO EVENT, SHALL SELLER’S LIABILITY, IF ANY, EXCEED THE NET SALES PRICE OF THE DEFECTIVE PRODUCT(S) PURCHASED DURING THE PREVIOUS CONTRACT YEAR.

Labor Allowance

Seller makes NO ADDITIONAL ALLOWANCE FOR THE LABOR OR EXPENSE OF REPAIRING OR REPLACING DEFECTIVE PRODUCTS OR WORKMANSHIP OR DAMAGE RESULTING FROM THE SAME.

Recommendations by Seller

Seller may assist Buyer in selection decisions by providing information regarding products that it manufactures and those manufactured by others. However, Buyer acknowledges that Buyer ultimately chooses the product’s suitability for its particular use, as normally signified by the signature of Buyer’s technical representative. Any recommendations made by Seller concerning the use, design, application or operation of the products shall not be construed as representations or warranties, expressed or implied. Failure by Seller to make recommendations or give advice to Buyer shall not impose any liability upon Seller.

Excused Performance

Seller will make a good faith effort to complete delivery of the products as indicated by Seller in writing, but Seller assumes no responsibility or liability and will accept no back charge for loss or damage due to delay or inability to deliver, caused by acts of God, war, labor difficulties, accidents, inability to obtain materials, delays of carriers, contractors or suppliers or any other causes of any kind whatever beyond the control of Seller. Under no circumstances shall Seller be liable for any special, consequential, incidental, or indirect damages, losses or expense (whether or not based on negligence) arising directly or indirectly from delays or failure to give notice of delay.

• FNW.COM

©2024 Ferguson Enterprises, LLC 0124 6171414 We reserve the right to modify or improve the designs or specifications of our products at any time without notice.

Read User Manual Online (PDF format)

Download This Manual (PDF format)

Download this manual  >>