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Backflow Enclosure - 100S-AL - Lift-Off - Safe-T-Cover



This 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 100S-AL enclosure is easy to set up, safe for testers, and helps offer protection from vandalism.

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

Pipe Size: 1"


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:

What You Should Know About Backflow Enclosures

Water supply systems are designed to maintain a specific water pressure allowing water to flow. The objective is to make sure the water inside pipes will not freeze or flow backward and prevent drinking and wastewater from mixing.  Backflow preventers or RPZs are used to accomplish this. These devices will need protection from the elements (cold weather and vandalism specifically) and backflow enclosures are used for this purpose.

Small Backflow Enclosure

Backflow Enclosure at Office Park

"Hot box" or backflow enclosures protect waterworks systems, (provided by utility companies, and commercial organizations) such as pumps and valves from damage caused by extreme weather. The enclosures also prevent freezing to guarantee you have a continual flow of water. The boxes are made of insulated metals, fiberglass, or thermoplastics and often have a built in heater.

Backflow Enclosures 101

Our article will cover what Hot Box backflow enclosures are, how they protect waterwork systems from freezing, and what you should know about these enclosures.

Tip: If you need to protect the landscape or turf on your next jobsite, we also have temporary turf protection mats that provide traction as needed for heavy vehicles or machinery.

Interior View of Backflow Enclosure

Internal View of Safe-T-Cover Enclosure

What Is a Hot Box Backflow Enclosure?

If you are looking for a hot box, you are looking for a heated enclosure to protect your waterworks system.

The legal standards that govern the design and installation of backflow enclosures is ASSE 1060. The enclosures must be tough to protect systems against elements including high winds and snow loads, that is the pile-up of snow and ice placing pressure on an enclosure. You also need to make sure your enclosure can be locked to prevent anyone from tampering with it which could lead to damage.

ASSE 1060 requires that enclosures have heaters to keep the temperature at a certain level no matter what the environmental conditions are. A Class 1 enclosure's temperature should be at least 40° F (4.4°C) even if the air temperature is below -30°F (-34.4°C).

Large Aluminum Enclosure

Aluminum Backflow Enclosure

High-Quality Protection

If you have an ASSE 1060 compliant backflow enclosure, you are getting excellent protection. These enclosures are put through quality control including dropping a 20 lb weight on the lock mechanism to record its resistance to impact.

If the mechanism is not damaged and functions properly it will pass the test. Afterward, the entire structure is tested to find out if it can support a vertical load of 100 lbs per square foot.

Testing and Maintenance

For an enclosure to be ASSE 1060 certified, it must be designed with testers and maintenance technicians' safety in mind.

For example, if the enclosure is so small that it cannot stand in properly, it must allow for any lid to be secured when it's lifted.

Now that you're more informed of the ASSE 1060 standard, you should put more effort into buying enclosures with the ASSE seal of approval. Such enclosures are a good investment for protecting your expensive equipment.

Cross-View of RPZ Enclosure

Insulation of Safe-T-Cover Enclosure

How Does Freezing Affect Waterworks Systems?

This can depend on its compressibility. Water does not contract when you squeeze it but heating and freezing expand the volume in non-flowing situations  Water will freeze and expand up to 9%. An expansion can lead to issues. For instance, an increase in pressure can rupture your piping system.

Can Backflow Enclosures Prevent Freezing?

The answer is in the insulation. Most hot box enclosures are made up of several layers of material which create small air pockets in the layers. Since air is not a good conductor of heat, it minimizes the amount of heat lost to the environment.

According to the Department of Energy, you can check the effectiveness of a material to find out its heat loss by determining its thermal resistance, known as the R factor.

In general, an enclosure with a higher R factor is better than one with lower thermal resistance. You want your backflow preventer to not lose heat and cause water to freeze during the wintertime.

When you are in the market to purchase enclosures, find out about the different kinds of insulators. They will come with either rigid or compressible insulators. CompressIble insulators are designed to maintain thickness and retain thermal resistance even when squeezed. On the other hand, rigid insulators are not particularly easy to compress.

Outside of compressIble and rigid material, insulators can be made up of open or closed construction. Open insulators can absorb moisture which reduces their heat retention abilities. Closed-cell insulation is designed to keep out moisture and therefore retain more heat.

Very Large Aluminum Enclosure

Large Backflow Enclosure at Industrial Site

Aluminum Enclosures

The Hot box backflow enclosures are in different sizes, designs, and styles. Even though they are in different manufactured forms, they are designed for quality and excellent performance.

If you want industrial quality and excellent durability, you should definitely look into aluminum enclosures. These enclosures are corrosion-free and UV resistant to keep waterworks systems in great shape for many years to come. You can also get riveted construction which comes with Mill and Marine grade finishes. As aluminum enclosures can be customized, they are perfect for larger projects.

These enclosures also come with bonded foam insulation that will not sag or peel from the walls.

What To Look for in Hot Box Enclosures

How can you choose an enclosure out of hundreds if not thousands of enclosures? Are these enclosures worth the money?

These are good questions. As we have discussed earlier on, what hot box backflow enclosures are, we should review some of the features you should look for.

Here are some factors you should consider:

  • Air Gaps Between The Insulation Layers: Because air is a poor conductor, air gaps between an enclosure's layers will harm its performance. When shopping for an enclosure,  make sure the enclosure does not have openings or gaps between the layers.
  • The Construction of The Walls In The Enclosure: Enclosures are designed to be outside, therefore the walls should be strong enough to withstand wind, moisture, UV, or other environmental elements. Pick an enclosure that is made of strong walls that can withstand many outdoor elements.
  • Space for Discharge From the Air Inlet: The loss of heat can happen because of poor insulation of the enclosure, through exposed piping, or even cold outside features such as a cold floor. It's really advisable to choose an enclosure with good space for the discharge from the air inlet or relief valve.  It should be designed to keep down the amount of water that can collect in the enclosure.
  • The Installation Pad:  The backflow enclosure will be mounted on the insulation pad. It should offer stability to prevent any extra stress on the walls and fasteners of the hot box enclosure. It should be secure and mount easily. Most manufacturers recommend permanent uncompromising pads such as concrete.
  • Appearance: Even though most enclosures come in the shape of a box, it should not prevent you from including some designs. If you are into landscaping, you might want to use an enclosure that will not detract from the surroundings. You can choose from aesthetic enclosures.  They are less noticeable and can even look like a rock or a custom design that will complement the landscape's features.

Overall, you should not rush into buying an enclosure. We recommend that you put some thought into it so you will pick the one that will withstand weather conditions, is very durable, and fits in your landscape naturally.

Always inspect where it will be installed and then consider any challenges you might encounter including temperature and wind factors.  You should pick an enclosure that is durable and will withstand all the elements.

Pay attention to the thermal features. Check the enclosure's insulation and heat requirements then make sure it's a reliable heater.

When Would Heaters Be Needed In Backflow Enclosures?

You probably know by now that your backflow enclosure will need a heat backup to keep insulated during colder weather. Most enclosures' inbuilt structures may not be able to replace lost heat as quickly as the temperature will drop. You may need an additional backup plan for your enclosure.

There are two different heat backups that you can use on your backflow enclosure. The first is an area heater which heats up space within the enclosure. The second is a radiant heater which heats up the piping or installation pad keeping your enclosure warm during colder weather. Either way, be sure to install electricity at the enclosure for heating.

Heated BackFlow Enclosure

Backflow Enclosure with Interior Heater

How Backflow Enclosure Heaters Work

Backflow enclosure heaters will add heat to your enclosure after the temperature drops, protecting pipes from freezing. Heaters come in two designs wall-mounted boxes, internal thermostats, or self-regulating cables.

When Will You Need Heaters

In general, any backflow enclosure that is located outside in an area that experiences freezing weather will need a heater at any given time of the year.

If you live in a warmer climate, does that mean your area has never experienced an occasional freeze? If you said no,  it's vital that you install a heater in your backflow enclosure.  It's better to be safe using enclosures that have heaters than not.


Hot box backflow enclosures are designed to protect waterworks systems including valves and pumps from damage caused by bad weather conditions or vandalism.

Hot box enclosures are made of several layers of material to protect your pipes and prevent an even bigger nightmare when they burst! In most cases, you will need a backup plan by providing heaters to protect your backflow preventers.