THE SAFE-T-COVER BLOG

Still Spec'ing the Watts 909? 3 Reasons to Switch to a 957 Assembly

It's time to switch from the Watts 909 to a 957 assembly. A few times each month, we receive a civil drawing and are asked to size and quote an enclosure to fit the Watts 909 reduced pressure zone (RPZ) backflow assembly. This assembly is well known in the industry, as it was introduced more than 30 years ago and is proven to get the job done. If a different Watts model was available that accomplished the same design intent and could save your client some money, would you start specifying it? You're about to learn more about the Watts 957, which has actually been on the market since 2002.

You'll Save Money

The upfront cost for the 909 is higher than the 957. The 957 is a newer design, has a shorter lay length and weighs less. The 909 and the 957 are both USC-approved backflow assemblies and have an outstanding track record in the field. Specifying a 957 will accomplish the same design intent and save your client money. We checked the pricing on a few supply websites. Below is a price comparison chart. You'll see the same pattern we did.

Assembly Type Supplyhouse.com - 4" Supplyhouse.com - 6" backflowpartsusa.com - 8" shopbackflow.com - 10"
Watts 909 $2639.95 $4049.95 $8525.08 $16816.39
Watts 957 $1699.95 $2897.95 $6775.75 $8097.99

In addition to saving money up front, you'll save it long term. Backflow assemblies are tested each year to be sure they are doing their primary job, which is to prevent backflow. As the backflow tester finds the assembly needing repair, the repair parts will cost more for the 909.

6WA957-OSY12You'll Save Space

The footprint of the 909 is longer than the 957. Whether it's installed inside the building or outside in an RPZ enclosure, the 909 takes up more room. The lay length of the 6” 909 is 66” long and the lay length for the 6” 957 is 43 ½”. When you install them inside, the assembly takes up expensive floor space. For a breakdown of just how much money an indoor RPZ can cost, check out this blog. Unfortunately, you'll run into a similar problem if you install a 909 outside in an RPZ enclosure. The enclosure must be significantly larger. We looked up the backflow enclosure requirements using our handy sizing guide and found the 6” 909 fits in model 600-AL. The contractor pricing for the 600-AL is $4,546. The 6” 957 fits in model 400T-AL with contractor pricing of $3,939. Once again, you're saving money - just over $600 - and you'll also save space. The smaller your enclosure is, the easier it is to make it aesthetically pleasing as well. Click the image to the right to see the 400T-AL enclosure with backflow assembly standard detail larger.

You'll Save Pressure

The pressure drop across the 957 is typically less than the pressure drop across the 909. The difference is small, but in some areas the smallest improvement in pressure can be precious. The pressure loss versus flow rate curve of a 6" 957 and 909 are below to illustrate this point.

909

957

909 pressure loss vs flow rate graph 957 pressure loss vs flow rate chart

Time for an Assembly Update

We're unsure why the 909 still shows up on so many design plans. The Watts 957 offers the same design intent as the Watts 909. By specifying the 957, the backflow assembly will be smaller, weigh significantly less, and even save your customer a few thousand dollars on the upfront cost. You'll save again if the assembly is to be installed outside in an enclosure because you'll get to use a smaller one of those as well. Then, enjoy the continued savings on maintenance and repairs. It's a no brainer: On your next project, think about the 957 instead of the 909.

aluminum enclosure

Related Posts

From the Field - The Safe-T-Cover Advantage with a Damaged Enclosure

Think Outside the Vault: Fayetteville, North Carolina

From The Field: 2022 WASDA Fall Conference Recap

Fire Pump Housing Options Beyond the Building

Heading into the unknown: Another Big Freeze could be catastrophic

3 Reasons Why a Backflow Cover Must Have Heat

Water 2050: Preserving the Future of Water

From the Field: Tips for Safe-T-Cover Enclosures and Protective PVC Coating

Why RPZ Valves Are Required and How to Install One

DC VS RPZ - WHAT'S THE DIFFERENCE?

From the Field – National Backflow Prevention Day

Forward thinking in Arlington, Texas: Leading the way with public health and backflow preventers

Texas Water Show 2022 Recap

The Drawbacks to Using a Backflow Cage

Quintessential List of Backflow Preventer Enclosure FAILS

Chicago Backflow Incident of 1933

Three Reasons Why You Should Choose an N-Type Device

IoT Takes Backflow Prevention To Another Level

The Right Backflow Insulation Cover & Heater For You | Backflow Cover

How Do You Hide A Backflow Enclosure?

How Does a Backflow Preventer Work?

This is How You Cut Backflow Preventer Installation Costs

This is How A Backflow Preventer Installation Should Be Done

Above-Ground-Backflow Assemblies Are a Big Winner in Las Vegas

A Backflow Preventer in a Utility Vault Can Be Deadly

How to Find the Perfect Enclosure for Backflow Prevention

How to Decide If You Should Repair or Replace Your Backflow Preventer

VIDEO: Safe-T-Cover Hopes To Change The Way You Think About Backflow

What You Need to Know About Backflow Prevention and Flood Risks

What is a Cross Connection Control and Backflow Preventer?

CONTAINMENT VS ISOLATION: THE COMMERCIAL BACKFLOW PREVENTER INSTALLATION BATTLE

Fields Presents a "Smart" Future for Backflow Preventers

When You Should Use Backflow Theft Prevention Cages

Why You Should Install Multiple Backflows in One Aluminum Enclosure

What we Learned About Underground Backflow Preventers During the Panel

Webinar: The End-All Discussion on Underground Utility Vaults

Cross Connection Control Managers Work Behind the Scenes to Protect Water Quality

Never Put Your Backflow Preventer Installation In The Basement

Enclosure VS PreCast Concrete Vault - First Cost Comparison

Roswell, GA Updates Standard Details For RPZ Backflow Preventers

Which Do You Need - A Cage or Enclosure?

Let's Get Back to the Basics of Backflow Preventers in Utility Vaults

Let the Civil Engineer Handle It: RPZ Backflow Preventers

Are Water Utilities Inheriting Risk Regarding Backflow Installation?

Keep Backflow Prevention Outside To Reduce Risk for M/P Engineers

This is The One Place You Should Never Install A Backflow Preventer

Cross Connection Alert - Poll Reveals Concerning Info on Vault Design

Backflow FAQ - Flooded Vaults, Standard Details, and RPZ Flooding

A Video on Why Vaults Are A Bad Idea For Backflow Installation

Risks Associated with Installing RPZ Backflow Preventers Inside

How to design & Buy a Pump Enclosure

Get the free, editable checklist.

download-cta
DOWNLOAD NOW

CONTACT US

Have a question about a backflow preventer enclosure?
Click the contact us button below and one of our experts will be able to help with your specific enclosure needs.