Spheres & Accessories

UniCast Spheres

Prover Spheres and Handling Accessories

UniCast Spheres Overview

Making Accuracy Seamless

The UniCast Sphere is a seamless, inflatable meter proving sphere with enhanced durability and unwavering precision. Each sphere features a design optimized for elasticity, wear-resistance, and operational lifetime, eliminating seam splitting and delaminating during service. Along with our exceptional factory support, our spheres have become ubiquitous in the Petroleum industry globally and the first choice for accuracy.

Features at a Glance

The unified exterior of the UniCast Sphere is molded into one inflatable continuous shell of polyurethane that prevents splitting and retains its “Sphericity.” While other two-piece spheres can inflate into an egg-shape, our one-piece construction helps the UniCast Sphere maintain a truer diameter, giving the most accurate measurement.

Two Weights

Our UniCast Sphere comes in two weights, Standard and Heavy. The standard weight UniCast Sphere is ideal for normal operations while the heavyweight UniCast Sphere should be utilized in high turbulence applications. In the weighted spheres, the weight is cast into the internal bladder, which will help contain the weight in the event of the catastrophic destruction of the sphere.

Low Friction

Offering a low friction sphere for dry, non-lubricating products to reduce sphere chatter. Tests have shown a 38% reduction of friction with this product.


We have several sphere accessories to aid with inflation and handling during routine maintenance and/or replacement.

What Durometer Do You Need?

50 Series

change model
50 Series Model Image
Model Specifications

    4″ min – 36″ max
    Standard or Heavy
    Low or Moderate


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Sphere Position Indicator

This device will give an audible and visual signal as the sphere passes the switch. Works with both Unidirectional and Bidirectional provers, and is available in both latching and non-latching configurations.

Manual Suction Cups With Handle

6′ Handle w/Chain Release
4′ Handle w/Chain Release
2′ Handle w/Chain Release
1′ Handle (Mini)

Sphere Sizing Rings

Sphere sizing rings are custom machined from lightweight .250 aluminum plate to customer specified sizes, allowing operators to check and reproduce the proper inflation size of the sphere. Rings are typically sized for 2% – 4% larger than the inside diameter of the pipe size. Sphere rings are available for all sizes of spheres.

Sphere Inflation Tool Kit


• Filler Adapter
• Valve Wrenches
• Core Extractor
• Sizing Tape Measure

(All tools can also be purchased separately.)

Sphere Inflation Pump

Constructed of lightweight aluminum with onboard tool kit.

Mini Manual Sphere Vacuum Extractor

Available with small cup only.

Cup can be special ordered in red, green or yellow urethane. (All cups are processed with 65 durometer urethane regardless of the color ordered)

Manual Vacuum Sphere Extractor

Available with small, medium, large cups.

Note: Cups can be special ordered in red, green or yellow urethane. (All cups are processed with 65 durometer urethane regardless of the color ordered)

Critical Lift Sphere Vacuum Extractor

Designed for the ability to lift over objects, providing continuous suction.

Critical Lift Sphere Slings

Sphere slings are made of high-quality nylon webbing, providing a convenient method for lifting heavy spheres. Sizes available for lifting 16″ to 36″ spheres.

Have Questions?

Product Support

From our floor to in-the-field, Meter Engineers products are manufactured and supported with rigorous detail. We proudly stand behind our products as a world-class support team; ready to assist customers when and how they need it. We are here for you.

Sales Inquiries

Do you need a metering solution for a specific application or flow rate on a job site? Or perhaps, you are looking for a custom prover product that delivers accuracy and dependability, but needs to adhere to some unique requirements? Contact our sales team, today!

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