Spherical Disc Valves

Engineered Valve Solutions for Powders, Dry Bulk Materials, and Slurries

GEMCO Valve, now part of The Strahman Group, designs and manufactures industrial process valves for the most demanding material handling applications. For decades, processors have relied on GEMCO spherical disc valves, also commonly referred to as segmented ball valves, for handling powders, solids, slurries, and bulk materials across pharmaceutical, food, chemical, battery, mining, and specialty chemical industries.

When powders, bulk solids, and slurries stop flowing, production slows, maintenance costs increase, and product quality can suffer. GEMCO Valve helps manufacturers maintain reliable material flow in even the most demanding processing environments. From sanitary food and pharmaceutical applications to abrasive, corrosive, and high-temperature industrial processes, our valve solutions are engineered to reduce downtime, minimize maintenance, improve containment, and keep production moving.

Industries and Materials We Serve

GEMCO Valve spherical disc valves are specified across four broad material categories. Each presents distinct flow and sealing challenges that conventional valves struggle with.

• Valves for Powders: Fine, cohesive, often hygroscopic materials that bridge over butterfly discs and pack into ball valve cavities. GEMCO VALVE spherical disc valves are used for pharmaceutical powders, active pharmaceutical ingredients (APIs), food powders, agricultural chemicals, dry catalysts, carbon black, metal powders, lithium salts, and hundreds of other dry materials.  See our “See our diagnostic guide to powder valve failures“
• Valves for Solids: Granular, pelletized, flake, and chunk materials that abrade conventional sealing surfaces and jam slide gate tracks. Applications include plastic pellets, granulated sugar, sodium chloride, iron ore pellets, ceramic particles, fertilizers, dry food crystals, and abrasive minerals.
• Valves for Slurries: Mixtures of solids suspended in liquid carriers that combine the abrasion of solids with the chemistry of liquids. Common slurry applications include pharmaceutical wet cake, lithium-ion battery electrode slurries, mining tails, ceramic slurries, alumina slurries, and sodium cyanide. See our “See our slurry valve specification guide.”
• Valves for Bulk Materials: System-level bulk handling applications, including silo and hopper discharge, pneumatic conveying, weigh stations, and batch transfer. Materials range from cement and limestone to flour, sugar, plastics, lithium compounds, and agricultural products.

Why Traditional Valves Fail in Solids and Slurry Service

Conventional ball, butterfly, and slide gate valves were designed primarily for liquid and gas service. Material bridging, product buildup, abrasive wear, and valve jamming can reduce process efficiency, increase maintenance costs, and create unplanned downtime. When pressed into powder, solid, slurry, or bulk material service, they exhibit three predictable failure modes:

• Bridging: Material arches across the valve disc or obstruction, halting flow and forcing operators to use vibrators, mallets, or ramrods to restart the process.
• Packing: Material compacts into tight cavities behind the closure element, eventually tearing the seat or seizing the operating mechanism.
• Jamming: Abrasive particles wear into the sealing tracks of slide gate valves or wedge into ball valve cavities, causing rising actuator torque, seat damage, and unplanned downtime.

 Read the full diagnostic guide to bridging, jamming, and packing“

Full Port Opening Eliminates Material Bridging

Many butterfly valves create flow restrictions because the disc remains in the material stream. Powders and bulk solids can bridge across these obstructions, disrupting flow and requiring manual intervention. The Gemco Spherical Disc swings completely out of the flow path, creating a true full-port opening that promotes mass flow, reduces bridging, and improves material discharge from hoppers, bins, silos, and processing equipment.

Self-Cleaning Sealing Surface Reduces Abrasive Wear

Abrasive powders and slurries can rapidly wear sealing surfaces in conventional slide gate valves by forcing material into the sealing track during operation. The Gemco Spherical Disc uses a wiping action that continuously clears product away from the sealing area. This self-cleaning design minimizes wear, improves sealing performance, and helps extend valve service life in demanding industrial environments.

No Pinch Points Prevent Material Buildup and Valve Jamming

Traditional ball valves contain internal cavities where powders and solids can become trapped and compacted. As material accumulates, operating torque increases, seals wear prematurely, and valve performance declines. Gemco’s Spherical Disc design eliminates pinch points and material traps, preventing buildup while maintaining smooth, reliable operation throughout the valve’s service life.

Configurating Your Valve for Service

Every GEMCO valve is configured to the specific demands of the application. The key decisions include:

• Body material: Cast iron, carbon steel, 316L stainless, Hastelloy, or titanium, matched to the chemistry of the process
• Seat material: Reinforced Teflon (RPTFE) for Class VI shutoff, metal seats for high temperature or extreme abrasion, or inflatable seats for high-cycle service
• Surface finish: Mill finish through #7 polish (Ra 10 to 15 microinch), with USDA/FDA and EHEDG options for sanitary applications
• Connections & mounting: ANSI 150 #, DIN, ISO 5211 actuator mounting, tri-clamp, quick clamps, butt weld, or custom
• Actuation: Pneumatic (double-acting or spring return), hydraulic, or manual, with electro-pneumatic positioners for automated control
• Fail-safe configuration: Spring return or double-acting with pneumatic accumulator

Internal link: “See our complete valve sizing, actuation, and integration guide for engineering detail on each of these decisions.”

Configurating Your Valve for Service

Every GEMCO valve is configured to the specific demands of the application. The key decisions include:

• Body material: Cast iron, carbon steel, 316L stainless, Hastelloy, or titanium, matched to the chemistry of the process
• Seat material: Reinforced Teflon (RPTFE) for Class VI shutoff, metal seats for high temperature or extreme abrasion, or inflatable seats for high-cycle service
• Surface finish: Mill finish through #7 polish (Ra 10 to 15 microinch), with USDA/FDA and EHEDG options for sanitary applications
• Connections & mounting: ANSI 150 #, DIN, ISO 5211 actuator mounting, tri-clamp, quick clamps, butt weld, or custom
• Actuation: Pneumatic (double-acting or spring return), hydraulic, or manual, with electro-pneumatic positioners for automated control
• Fail-safe configuration: Spring return or double-acting with pneumatic accumulator

Internal link: “See our complete valve sizing, actuation, and integration guide for engineering detail on each of these decisions.”