Essential Fittings and Accessories for Chemical Storage Tanks

Storage tank accessories and fittings are often seen as extra add-ons that get little consideration — as if they were nice-to-have features like heated seats in a new vehicle. However, these are critical components of a successful storage system. The useful life of your chemical storage tank can be greatly impacted by your choice of fittings and accessories. 

Our goal at Poly Processing is to bring you safer, smarter tanks and fittings that make chemical storage easy for you. That’s why we carry hundreds of specialty fittings and accessories for chemical storage. This article highlights some of the more important products that you should consider when purchasing your next chemical storage tank.

Chemical Storage Tank Fittings

Enhanced Bellows Transition Fitting for the SAFE-Tank®

The Enhanced Bellows Transition Fitting is a secure yet flexible, fully contained SAFE-Tank® bottom discharge fitting. This fitting incorporates an expansion joint, allowing the tank to expand freely during loading and unloading, and it virtually eliminates damage from piping vibrations caused by pumps.

With this performance-maximizing fitting: 

• Containment of the expansion joint eliminates the threat of uncontained chemical leaks and dangerous “spurts.”
• Piping layouts can be fully contained by connecting a dual-wall piping system onto the fitting. This can mean a safer workplace and less threat to the environment. Unsurpassed containment of discharge is allowed on a SAFE-Tank®.

B.O.S.S. Fitting

With its streamlined one-piece design, the B.O.S.S. Fitting® reduces the seal point to a single gasket to greatly reduce the chances of leakage.

This unique fitting:

• It is constructed of polyethylene for chemical compatibility with your tank.
• Has an innovative backing ring design to reduce stress on the fitting and make it three times stronger than plastic fittings.
• Is easy to maintain, since the pipe connection is extended beyond the sidewall of the tank.
• Is available in 1, 2 and 3 inches I.D. with PVC or CPVC socket connection.

IMFO® Fitting

Traditional tank maintenance can be a challenge with many chemicals – so Poly has developed a unique system that helps minimize the hazards associated with traditional vertical tank maintenance.

Poly Processing’s Integrally Molded Flanged Outlet (IMFO®) Tank is a homogenous flange system that is molded as a unified part of the tank while it is being manufactured, making it a stress-free fitting in the tank. The flange is created from the same material as the tank — it’s not an insert added during or post-production.

Some companies create tanks out of one substance and insert a metallic flange or metallic insert during production or post-production, for drainage and discharge. This reduces the cost of investing in proper tooling to make the right tank. Unfortunately, an inserted metallic flange/insert is common in the tank industry. However, there are incredible benefits to using a molded full discharge fitting or IMFO.

Some of the advantages of the IMFO include:

• Full tank discharge, because the flange is at the bottom of the sidewall, below the tank knuckle radius. There’s no need to enter the tank for cleaning.
• Enhanced long-term performance and greater useful life of the tank since the flange doesn’t compromise the tank’s hoop integrity or structural design.
• Complete flange face protection in aggressive oxidation environments. The antioxidant OR-1000™ system protects the discharge components from deterioration.
• Highest amount of static head pressure. The IMFO’s design brings you the highest net positive suction head (NPSH) of any vertical non-coned tank on the market.
• Any required maintenance is simple and hassle-free. Unlike metallic inserts, the flange extends away from the tank wall and the entire flange system is external with easy hardware access from outside the tank.

In addition, the IMFO presents no chemical compatibility issues like the ones you may encounter with metallic inserts. If the chemical is safe in a crosslinked polyethylene tank, it’s safe discharging out of the IMFO system.

Bulkhead Fittings 

These economical fittings are best used on smaller tanks in mild applications. They can be installed on the sidewall, overflow, or dome. They may also be used as an overflow fitting with all chemicals, since it’s non-wetted. 

Bulkhead fittings must be installed from the inside of the tank, which requires tank entry for repairs and maintenance. They should not be used on the bottom sidewall of tanks greater than 3,000 gallons or tanks greater than 6 feet in height.

Universal Ball Dome Flanges

Universal ball dome flanges are “self-aligning,” which allows for vertical plumbing on the dome of the tank up to 22 degrees. The fitting can be repaired and maintained externally without tank entry. Available with Ryton® bolts, an economical alternative to titanium, C-276, and Alloy 400.

Universal Ball Dome Bulkheads

Our Universal Ball Dome Bulkheads are also “self-aligning,” which allows for vertical plumbing on the dome of the tank. This option is an economical alternative to UBD flange-style bulkheads, since no additional bolts are required.

NOTE: These fittings are for top-use only.

Chemical Tank Accessories from Poly Processing

Reverse Float Level Gauge

Poly Processing’s reverse float level gauge consists of a float inside the tank, which bobs on the surface of the chemical. The float is compatible with any kind of chemical that can be stored in a Poly Processing tank. The float is attached to a rope, which travels through a clear vertical pipe on the outside of the tank. A level indicator is attached to the end of the rope.

As the tank is filled, the chemical lifts the float inside the storage tank, and the level indicator on the outside is lowered. As a reverse gauge, the level indicator shows the reverse of a tank’s level—the lower the indicator, the fuller the tank.

The reverse level gauge uses a pulley system with polypropylene rope, nylon rollers inside of PVC elbows, clear pipe, and a level indicator. The external components are dry-fit together, not glued. Assembling and replacing the gauge is easy and only takes a few minutes. Maintenance is simple, and individual pieces can be replaced, if needed.

While the level indicator isn’t intended for precise monitoring or metering, it reliably provides a basic, easy to read indication of your chemical storage tank’s capacity. The gauge is ideal for facilities that need to know when to refill their tanks, but don’t need precise volume numbers.

The reverse float level gauge provides several benefits, including:

• No stains on the clear pipe from chemicals or UV attack
• No siphoning of the tank if the pipe breaks, because there is no chemical in the external pipe
• The internal float is designed to work with 1.0 to 1.8 specific gravity fluids
• No chemical burns or chemical spurts on operators
• Reverse calibration tape can be added for tank capacity
• Provides mechanical verification of ultrasonic or other electronic level sensor 

The reverse float level system can be used on almost any tank, including double-walled SAFE-Tanks®. There are different dome mounted fittings used for the reverse float gauge. If the fitting is installed on the flat you can use a PVC or SS bulkhead fitting. On the curvature of the dome you must use the universal ball dome fitting or made vertical curved fitting.

Fill Lines

When you’re filling your chemical storage tank, it is important to ensure the safety of employees and equipment and to prevent loss of product. A fill line helps prevent spills while making it easy and efficient to fill the tank.

A fill line is a specially designed pipe system that is attached to the tank. The majority of fill lines are composed of PVC or CPVC to ensure chemical compatibility. It normally comes with a ball valve and a quick disconnect camlock system to keep the line from transferring chemical when not in use. Fill lines are available in several configurations, including internal, external and combination. An anti-foam elbow is another option that can be used as a substitution for an internal fill line.

The best fill line for your needs depends on your chemical application and the configuration and placement of your tank system. Whether you choose to install an internal, external or combination fill line, it will need to be properly anchored to the tank. A properly designed support ensures that the line is durable and stable if a truck or piece of equipment inadvertently bumps the line.

Venting

Polyethylene chemical storage tanks require correct venting installation for two essential reasons. First, venting ensures the safe operation of the tank and the chemicals stored under pressure within the tank. Secondly, proper installation is vital to maximize the life of the chemical storage tank.

A crucial factor impacting the safe operation of the poly chemical storage tank and maximizing the useful life of the tank is proper and safe venting of the tank.

Poly Processing offers several different styles of vents, depending on the end use application. Here are just a couple of our more popular venting products:

U-Vent

Standard venting for outdoor tanks or for storing chemicals that create fumes. In PVC, in sizes 2 to 6 inches.

8″ Mushroom Vent Assembly

Until now, space-consuming (and expensive) large vents or multiple vents were necessary to meet venting requirements in order to maintain the warranty. Our solution is an 8” mushroom vent, which is available as a complete assembly in a standalone version. This mushroom vent has been used by Poly Processing Company for several years as part of the F.S. 2650 manway cover. 

The vent now comes with a flange molded into it so that it can be installed on the dome of the tank to give you greater venting capacity. This is a more cost-effective alternative to many other venting systems.

Check out our venting page for a full assortment of vents and venting products.

Heat Pads and Insulation

Poly Processing’s tank heating systems are specifically designed for temperature maintenance of polyethylene tanks. SilcoPad® tank heating systems maintain a desired product temperature, not to exceed 100 degrees F.

Each heating system consists of tank heating pad(s) and a temperature controller. The quantity and type of SilcoPad® tank heating pads required is determined by the size of the tank, the desired temperature maintenance and environmental conditions.

Tanks are available with standard heating systems with a Delta T of 30, 60 and 100 degrees F.

Tanks are typically supplied with the heating panels and a controller installed by Poly Processing. The only field connection required is a power supply to the heating system.

For a complete list of our inventory, with prices, contact your Poly Processing representative. The representative can also help you determine which products are most suitable for the chemical you are storing.

Industry News

For over five decades, Poly Processing has been at the forefront of innovation in chemical storage tank design and manufacturing. Reinforcing our commitment to advancing high density crosslinked polyethylene (HDXLPE) tank technology, we are thrilled to unveil our latest update to our  vertical storage tank solutions: the 15,500-gallon IMFO tank, the 15,000-gallon Sloped Bottom IMFO tank, and the 15,500-gallon Vertical tank, are all available in specific gravities up to 2.2 design.

These large innovative HDXLPE tanks are designed for exceptional durability, reliable performance, and an extended lifespan across a variety of applications. To enhance protection and prolong service life in oxidative environments, such as those involving sodium hypochlorite, they can be manufactured with our industry-leading OR-1000 engineered resin system, known for its remarkable resistance to oxidative chemicals.

These tanks represent the best engineering and design in the tank manufacturing industry, and they are covered under PPC’s industry-leading warranty.

At Poly Processing, we’re focused on delivering high-quality, forward-thinking solutions to meet the evolving demands of the chemical storage industry.