Using a Universal Ball Dome Fitting (UBD)

Universal ball dome fittings, or UBD’s, have a moveable ball inside the fitting, which can only be installed on the dome of the tank, as this fitting is not considered a leak-tight fitting. The fitting has a compression nut that locks down the ball after you install the flange or bulkhead, allowing connections at angles up to 24 degrees. The UBD fittings can be installed on the dome of the tank to give the end user more options for fitting placement. Let’s take a look at the uses for these types of fittings and their advantages.

Advantages of a UBD

UBDIn a situation where vertical plumbing is needed, it is usually necessary to install a fitting on one of the molded-in boxes or runway flats on the dome of the tank so that the connection can be mated vertically to plumbing. With a UBD, the ball inside the fitting rotates up to 24 degrees, so the fitting can be installed directly on the dome allowing for vertical connections as well.

UBDWhether you choose a bulkhead or flange style UBD is largely your preference. Poly Processing offers both styles.

Instances Where You Can See The Difference

In instances where reverse float gauges are installed, you want to make sure the fitting coming out of the top of the tank is vertical. In some cases, end users will choose the dome portion of the top of the tank for the reverse float gauge installation.  The UBD fittings work well in this application and save the end user the cost of having a custom welded fitting. These custom welded fittings are expensive because it is hand welded to the angle of the dome of the tank and in some cases can change alignment over time due to changes in temperatures of the tank which leaves the fitting out of calibration.  A UBD fitting usually has a nipple inserted into the fitting end and either a thread or slip pipe connection for the on site plumbing installation. Poly Processing can install a mating flange to the pipe giving the end user the opportunity to make flanged connections out of the top of the tank.  

A UBD can be used in almost every storage application, but they are especially useful in situations where ultrasonic devices are used. Often, people will install large (sometimes 6 inch) made-level fittings to install the ultrasonic level sensor from, which isn’t necessary. The UBD fittings have the adjustable ball and the ultrasonic level sensors typically have 2 connections that fit right into the ball. This gives the end user a vertical ultrasonic level sensor at a much more competitive cost.

The UBD is also helpful in internal and external combination fill lines where the customer would like to install a fitting on the dome. The UBD fittings allow the downpipe and fill line to attach to the top of the tank vertically.

This is one of the many innovations Poly Processing offers to enhance the value of the chemical storage system and make it cost effective for our customers. To learn more, reach out to a chemical storage expert. 

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Topics: Fittings and Accessories