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> New watts 909L 4" backflow preventer,
New watts 909L 4" backflow preventer,
For Sale: New watts 909L 4" backflow preventer,
Subject New watts 909L 4" backflow preventer,
Ad is submitted by poster:
Industry Surplus is a service of Motor City Composites, a leading supplier of tooling, prototype and production materials and services. MCC has over 85 years combined experience within the Automotive Adhesive Bonding, Rapid Prototyping and Composites markets. This experience has been invaluable in evaluating and selecting high quality surplus, used, repossessed and prototype equipment to offer for resale.
Description: 4" Backflow Preventer
Watts 909L 4" Backflow Preventer
New in Crate with Installation and Service Guide
flow to a higher pressure zone.) When the supply line pressure drops to a vacuum (pressure less than atmospheric), it is impossible to maintain a reduced pressure zone. Backflow/back-siphonage protection then can only be achieved by allowing air to enter and break the vacuum. With the vacuum under control, the siphonage effect ceases
and the potentially dangerous polluted or contaminated water is then drained out of the relief valve before it reaches the water supply (see Figure 3). Vacuum relief is most important should the spring loaded checks become fouled (see Figure 4) during a reversal of flow which can displace debris. Back-siphonage through a reduced pressure principle assembly requires some method of preventing the vacuum from forming. Allowing the air to enter, which breaks the vacuum, which caused the siphon, is
necessary for the water to safely discharge, i.e., Air-in/Water-out Concept.
The valve has two channels; one for air-in to relieve vacuum, one for water-out for protection of the water supply. When the relief valve opens, one channel admits air to the top of the reduced pressure zone; the other channel then drains to atmosphere.
The principle is simple. Watts 909 series is the only backflow preventer to provide so much valve and so much protection.
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Posted By: Annabelle Miles
Contact: annabelle-miles@repair--parts.com (Annabelle Miles) (this is a temporary forwarding address).
