Install Instructions

ManualsBrandsWatts ManualsBackflow Preventers9DM2, 3/4" Brass Dual Check Valve with Intermediate Atmospheric Vent

Field Testing Procedure

Series 9D Backflow Preventer with Intermediate Atmospheric Vent

EQUIPMENT REQUIRED: Valve must be installed per drawing and one (1) flexible hose

with adapters furnished for testing.

Installation Providing for Field Testing

Test No. 1

Purpose: To check operation of air break.

Requirements: When supply pressure drops to atmospheric, air break must relieve pressure between both

checks.

Procedure: Close shutoff valves No. 1 and No. 2. Open test cock No. 2.

Observe: Some water should drain from vent indicating that diaphragm has lifted off its seat and

opened the chamber between the checks to atmosphere.

Test No. 2

Purpose: To test for tightness of second check Valve.

Requirement: Second check must be drip tight when pressure is applied to downstream side of valve.

Procedure: Close shutoff valves No. 1 and No.

2. Open test cock No. 2. Connect

ﬂexible hose from test cock No. 1

to test cock No. 3. Open test cock

No.1 and No. 3 admitting line

pressure to downstream side of

second check valve. Water must

not drip continuously from vent.

If water drips continuously from

vent, second check is leaking.

Series 9DM2, 9DM3

Dual Check with Atmospheric Vent

Sizes:

⁄2",

⁄4" (15, 20mm)

Note: Model 9DS - Remove union connections before sweating

• The 9D Dual Check with Atmospheric Vent is designed for use on non-health hazard,

continuous pressure, point of use applications for protection against backsiphonage

and backpressure. Install in accordance with the local codes.

• Remove union connections before sweating.

• For the best system performance, install on the fresh water feed line before any pres-

sure regulators (such as the Watts Series 1156 on a residential boiler application).

• Flush the line before installing the unit to remove any solder, flux or pipe chips. Clean

the strainer every six months or as conditions require.

• Some discharge is expected, particularly on start-up, until all seating surfaces seal.

Continuous discharge is an indication that the internal seating parts and surfaces may

require the cleaning.

• May be installed horizontally or vertically.

• Quick closing valves, water hammer or supply pressure fluctuations can cause inter-

mittent discharge. The installation of a Water Hammer Arrestors (Watts Series 05) or

Water Pressure Regulator (Watts Series 1156 or 25AUB) may be required to correct

the problem.

• Important: It is important not to install where the discharge could cause damage.

Pipe the discharge line in accordance with local code requirements. A physical air gap

must be maintained between the discharge pipe and the drain or sump. Create the

air gap by cutting the pipe on

a 45° bevel, at a distance of

12" above the floor. If used

on boiler applications do not

use an air gap fitting at face

level so as to prevent personal

injury from scalding water or

steam. In no event should the

vent opening or drain line be

plugged.

• If local codes require the

device be tested it must be

installed as shown in the

drawing on the reverse side.

RP/IS-9D

Limited Warranty: Watts Regulator Co. (the “Company”) warrants each product to be free from defects in material and

workmanship under normal usage for a period of one year from the date of original shipment. In the event of such defects

within the warranty period, the Company will, at its option, replace or recondition the product without charge.

THE WARRANTY SET FORTH HEREIN IS GIVEN EXPRESSLY AND IS THE ONLY WARRANTY GIVEN BY THE COMPANY

WITH RESPECT TO THE PRODUCT. THE COMPANY MAKES NO OTHER WARRANTIES, EXPRESS OR IMPLIED. THE

COMPANY HEREBY SPECIFICALLY DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT

LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

The remedy described in the first paragraph of this warranty shall constitute the sole and exclusive remedy for breach

of warranty, and the Company shall not be responsible for any incidental, special or consequential damages, including

without limitation, lost profits or the cost of repairing or replacing other property which is damaged if this product does not

work properly, other costs resulting from labor charges, delays, vandalism, negligence, fouling caused by foreign material,

damage from adverse water conditions, chemical, or any other circumstances over which the Company has no control.

This warranty shall be invalidated by any abuse, misuse, misapplication, improper installation or improper maintenance or

alteration of the product.

Some States do not allow limitations on how long an implied warranty lasts, and some States do not allow the exclusion

or limitation of incidental or consequential damages. Therefore the above limitations may not apply to you. This Limited

Warranty gives you specific legal rights, and you may have other rights that vary from State to State. You should consult

applicable state laws to determine your rights. SO FAR AS IS CONSISTENT WITH APPLICABLE STATE LAW, ANY IMPLIED

WARRANTIES THAT MAY NOT BE DISCLAIMED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO ONE YEAR FROM THE DATE OF ORIGINAL

SHIPMENT.