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RPZ Enclosure



The RPZ Enclosure is an American made back flow enclosure features a lift-off design for maximum accessibility, and comes with an ASSE Standard 1060 compliant drain flap. It is recommended to add the Chromalox Heat Cable #30 with 90W of heat to protect from freezing temperatures. This enclosure is made from marine grade aluminum, polyisocyanurate foam insulation board, and a glass fiber reinforced facer on each side. The enclosure is easy to set up, safe for testers, and helps offer protection from vandalism.

Dimensions: 7" W x 32" L x 22" H


Model: 100S-AL

Weight: 26 lbs

Dimensions: 7" W x 32" L x 22" H

With or without 90W Heat Cable
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  • Marine-grade aluminum construction material
  • All models are lockable for vandal protection
  • Easy access for testing and repairs
  • ASSE Standard 1060 compliant drain flap
  • Easy installation
  • Offers freeze protection when used with the recommended heat
  • Made in the USA


✔  All items ship for free (standard ground, see map)

☏  Call: (800) 583-4891 for pricing and shipping questions.

Shipping estimates shown on the map pertain to this specific product only. Orders typically ship within 24 business hours. Transit times displayed in the map are listed in business days, and are approximate. The day that the order is shipped is not counted as a transit day.

Other Backflow Enclosure Sizes and Models:

Preparing An RPZ Backflow Assembly For Winter

What Is An RPZ Valve?

RPZ valves are critical for stopping toxic chemicals, hard metals, pesticides, hard metals, and other harmful poisons from entering the water. It's often used in irrigation systems, and fire prevention systems where it serves as a safety net.

In order to care for irrigation systems during a freeze, you have to winterize and protect the above-ground RPZ backflow assemblies to stop trapped water from freezing, expanding, or causing damage.

If you have the valves set up correctly, your RPZ can be turned off and drained. Also, you can wrap and insulate them in order to use them during the winter months. Wrap the RPZ side pipes with a foam pipe wrap and then tape them with heavy rubber tape. That said, some people prefer using R-11 fiberglass insulation instead. The actual RPZ valve is in the center so you should not totally wrap it as water must be able to drain from the bottom of the valve.

Hot box enclosure with lid open

Safe-T-Cover with Lid Open

In order to protect the center valve take an insulation pouch and place it over the top of the RPZ. Make sure the bottom section is left open. The pouch is attached to the ground using small stakes. To help cut off the wind, a layer of mulch can be added around the base of the pouch.

A kind of insulating enclosure or a box can be placed over the “bagged” RPZ for added protection from freeze while adding another layer of mulch at the base. You can purchase these pouches or boxes or make them yourself.

Some enclosures are decorative rocks with foam wall structures that can be left in place all year round. If you make your own enclosure, insulate it with spray foam or tape R-11 fiberglass insulation on the inside.

With all safety measures in place, you can run your irrigation system all winter long. You can decide to leave them on all year round or choose to remove them in the spring when the threat of freezing has passed, then replace them in the fall.

How To Choose The Right Backflow Insulation Enclosure and Pouch

Here are some tips for choosing the right insulation enclosure for your RPZ assembly. These enclsoures are often referred to as blankets, bags, covers, or jackets. You need to measure the RPZ in order to get the right size enclosure.

For measuring height, go from the ground up to the top edge of the valve.

For measuring width, go from the outside edge of one pipe to the outside edge of the other pipe.

Read the specs and look for the following:

RPZ Enclosure Installation

Installing a RPZ Enclosure


This indicates the level of protection from the cold. The higher the R-Value, the higher the protection. Any number higher than 10 is good protection from solid frost. If you will be placing a hard enclosure over the RPZ. Provide a wind break, you can go lower than 10 for the R-Value.

UV Protection

Ensure the material in the pouch is UV resistant to prevent deterioration.

Moisture Resistance

Get a pouch that resists moisture. Insulation fibers will lose their R-Value when they are wet and will rot caused by mold and mildew. Your best option is heat-sealed products.

Grommets (Specific to Pouches)

Are rings or edge strips. When it's windy, use these grommets to secure the pouch with zip ties. For added security, use wire locks or plastic security seals.

During Winter Months

During the winter, lawns go dormant and therefore do not need much water. But, to keep a healthy root system that will support new growth n the spring, you should have root insulation during the winter months. During cold weather, you should water your lawn once or twice a month.

With your RPZ insulated and running properly, you can use the controller to adjust the zone run times to a percentage of the summer schedule. Only water on your scheduled days and times.

There are several sensors you can install to work with your controller for better irrigation and help you out in the winter.

Housing for RPZ

Aluminum Enclosure for RPZ

Rain Sensors

Some sensors turn off as soon as it starts raining while others turn your system off after a certain amount of rain has fallen.

Freeze Sensors

These sensors will turn the irrigation system off when the programmed temperature is reached. Most people have them set to 35°F.

Weather-Based Smart Controllers

These controllers use real-time local weather information to adjust irrigation schedules. The controller can skip cycles based on users decisions, moisture of soil, freeze temperatures, amount of rain, and wind speed.

Winter irrigation can benefit your lawn and prevent expensive problems in the spring when the system is not used as often. Some problems include:

  • Clogged sprinklers with dry dirt, dust, and roots
  • Stuck valves
  • Dry, split valve diaphragms
  • Dry cracked sprinkler seals and gaskets
  • Growth of algae in stagnant water
  • Insects stuck in sprinklers

Running the system can move stagnant water out of the pipes, seals, gaskets, valve diaphragms, and will blow roots, dirt, and insects out of the system.