Industrial Valves for Solids Handling Applications

Engineered to Eliminate Bridging, Packing, Material Build-Up, and Premature Valve Wear

Choosing the Right Valve for Solids Handling

Unlike liquids and gases, solid materials behave unpredictably during processing. Particle size, bulk density, moisture content, abrasiveness, and flow characteristics can cause bridging, packing, rat-holing, material build-up, excessive actuator torque, and premature valve wear. Selecting the right solids handling valve is essential for maintaining reliable flow, minimizing downtime, and protecting process equipment.

GEMCO Valve engineers custom valve solutions for demanding solids handling applications. Our spherical disc valve designs are specifically developed to improve material flow, reduce maintenance, and deliver dependable shutoff across a wide range of industrial processing environments.

Why Traditional Solids Valves Fail

Explore the common challenges associated with processing different solid materials and learn how GEMCO Valve solutions improve reliability, reduce maintenance, and optimize material flow across a wide range of industrial applications.

GEMCO Valve's solutions for solids bridging

Full Port Openings

Unlike a butterfly valve the shutoff disc swings completely out of the flow of the solids preventing bridging and promoting mass flow.

GEMCO Valve's solution for solids jamming

Self-Cleaning Areas

Unlike a gate valve, the self-cleaning action tends to wipe the solids away from the sealing area instead of jamming abrasives into the sealing track.

GEMCO Valve's solution for solids packing

No Pinch Points

With a spherical disc or dome valve shape there are no tight cavities for solids to pack and jam-up causing the seat to tear or the operation to cease.

Common Solids Our Valves Can Process

Abrasives
Activated Carbon
Adipic Acid Powder
Aerated Magnesium Oxide
Aluminum Oxide
Aluminum Powder
Anode Battery Mix (Zinc & Gelling agent)
Baking Soda
Bentonite Clay
Carbon
Carbon Black
Ceramic Particles
Ceramic Slurry
Chemical Powder
Chloride Salts
Coal
Coke
Concrete Mix
Dry Catalyst
Dry Crystals
Dry Food Powders
Dust
Explosives
Ferrous Briquette
Fine Nickel Powder
Fine Peat
Fine Powder
Fine Solids
Flavors
Flour
Food Grade Dry Crystals
Glass Cullet
Glass Fine Grains
Glass Powder
Graphite
Ground Limestone Powder
Gypsum
Hard Plastic Pellets
High Nickel Cathode Active Materials

Inconel Powder
Iron Ore Dust
Iron Ore Pellets
Lead
Lead-Lithium Eutectic
Leonardite
Lithium
Lithium Salts
Magnesium Oxide Powder
Magnesium Powder
Manganese (Mn)
Metal Oxide
Metal Powder
Metal Powders In Inert Gas
Metal Sulfide Ammonium Salt
Mushrooms Soil and Spore Materials
Neutraceuticals Supplement Powders
Nickel Powder
Phosphorus Pentoxide
Pigments
Plastic Flake
Plastic Particles
Plastic Pellets
Plastic Polymers Pellets
Plastic Powders
PVC Ingredient Powders
PVC Resin and Plasticizer
Resin
Rock Salt
Salt Base
Salt Grains
Sand
Sawdust
Silica
Silica Sand
Silicon Dioxide
Slurry
Slurry Mud (Solid) And Water
Sodium Carbonate

Sodium Chloride Salt
Sodium Ethoxide
Solid Powders
Solids Powderlike Granulate
Soy Bean Flakes
Soy Protein
Soy Pulp
Soybean Meal
Specialty Chemicals
Spices
Stainless Steels
Starch
Starch Powder
Sticky Powder
Sugar
Sulfuric Acid
Tetrabromobisphenol A (TBBPA)
TiO2
Titanium Dioxide
Titanium Powder
Tobacco Powder Fines Scraps
Tomatoes
UHMWPE
UHMWPE Resin
Versal Alumina
Very Fine Like Talc Powder
Very Fine Metallic Powder
Volatile Alcohols
Walnut Shell
Wastewater Incinerator Ash
Wet Cake
Wet Filter Cake/Pharmaceutical
Wet Soya Fatty Powder
Wheat Flour
Whole Corn
Zinc / KOH
Zinc Fortification

Valve Options & Customization

What material options are there?

The solids to be processed will dictate the product contact material. Cast iron, carbon steels, and aluminum can be used for many industrial applications. Corrosive processes will call for the use of stainless steel, and in some cases material laden with solvents or other corrosives will justify the extra expense of using Hastelloy‚ or other high nickel alloy to prolong valve life.

For stainless steel valves of welded construction, 316L grade is preferred. It is more corrosion resistant than 316 stainless steel, and the lower carbon content prevents carbon precipitating from the welded joints.

What seat materials are available?

Very abrasive material will tend to dictate using metal seats versus the more commonly used reinforced Teflon seats.
The metal seal will give longer life and can be used at higher temperatures than Teflon but the shut-off sealing is limited to dust tight, ANSI class IV or ANSI class V. Reinforced Teflon can be used up to 450 degrees F (230 C), and provide Class VI shut-off.

What is the cleanability?

The sanitary requirements of the process will govern the surface finishes and other sanitary options. We define our finishes as follows:

No surface finish (Ra) specified. Sometimes referred to as “mill finish” or “as cast”. Fabricated valves will only have the internal welds ground smooth and flush. Common in general industrial applications where cross contamination or cleanability are not a concern.

#2 finish – Ra 33 to 65 microinch – 150 to 180 grit. Also referred to as “buffed, blended or uniform appearance finish”. Often specified for the outside of equipment that will be washed down.

#4 polish – Ra 16 to 32 microinch – 180 to 240 grit. All fabrication and handling marks removed. Surface is buffed to a uniform satin finish. The #4 polish is typical for the interior of equipment that needs to be cleaned between batches to prevent cross contamination.

#7 polish – Ra 10 to 15 microinch – 240 to 320 grit. All surface imperfections are repaired. Often referred to as “pit free” and “mirror finish”. Used for high purity applications such as processing potent pharmaceutical actives. Also used for products that tend to adhere to surfaces.

For automatic cleaning, spray balls or jets should be considered. Another option is a valve that can be dismantled by hand for inspection and cleaning. For safety reasons the size of such valves are typically limited to an 8″ port diameter due to the weight of individual components.

How much does the valve weigh?

The weight of a valve is especially important for mobile or rotating equipment. High performance and heavy-duty models can weigh four times as much as its regular-duty counterpart. Dust tight, full vacuum, and 1 bar service, is considered to be regular duty service. 90 PSI (6bar) to 150 PSI (10bar) is high performance. An 8-inch manually operated regular duty valve can weigh 55 lbs (25Kg), versus nearly 200 lbs. (90Kg) for an 8″ high performance model.

What are the mounting arrangements?

The typical ANSI 150 # and DIN drilling is used as an industry standard for heavy duty and high performance models. Quick clamps can also be used for applications up to 30PSI (2bar) and port sizes up to 8″.
Some valves will include blind tapped holes, which may be a problem if the valve is mating with existing blind tapped holes. Another option is to choose oversized flanges, which allows for through holes. For regular duty service valves, ANSI and DIN bolting can be overkill and alternative bolting patterns are available.

How is actuation handled?

As with other quarter turn valves; levers, gear drives or chain operators are available. Pneumatic and hydraulic, operators are available in double acting or fail-safe modes. Pneumatic operation should be the first choice for price, reliability, and speed. When handling solids a higher factor of safety is used to calculate seat torque requirements. The factor is typically 1.5 instead of the 1.25 used for liquid and gas valve calculations.

For solids that “set-up” or harden oversized actuator and specially designed discs that can break through the hardened cake are used. Actuators are typically sized for 80-PSI (5.3 bar) pressure. If the available supply air pressure is dependably higher (100 to 120PSI) or lower (40 to 60 PSI), this will factor in the sizing of the actuator.

For fail-safe operation, spring return actuators are the norm. When a spring return type actuator is used, it is oversized to compensate for the spring as well as the unseating, run, and seating torque required for valve operation. This can lead to weight and space problems as well as extra cost. An alternate fail-safe option is to use a double acting actuator with a pneumatic accumulator sufficiently sized to close the valve. If there is a loss of pneumatic pressure, a pressure switch activates the accumulator and operates the valve.

What kind of flow control is possible?

Fast acting (1 to 5 seconds), quarter turn valves are ideal for flow control of solids. A pneumatic (3 to 15 PSI) or electro-pneumatic (4 to 20 milliampere) positioner can take a signal from a manual adjusted pressure regulator, or from a computer controller. The pneumatic positioner is often used in manually operated filling stations, while the electro-pneumatic positioner is typical for automatic loss-in-weight systems.