Sealant Equipment, Inc. - Metering Principles

Positive Rod Displacement Image

This metering method is true positive displacement metering and with the fewest parts is considered the most reliable dispensing system. Fluid is loaded into the meter when the rod retracts from the cylinder. Fluid is dispensed when the rod enters the cylinder and displaces material. This is also called Single-Acting metering since material is dispensed in one action of the rod. This metering method is used in 1-Part Dispensing Systems and 2-Part Meter-Mix Dispense Systems.

Piston Displacement Image

Piston Displacement

This positive displacement metering method uses a piston on a rod to dispense material. Fluid is loaded into the meter when the piston retracts from the cylinder. Fluid is dispensed when the piston enters the cylinder and displaces material. This is also called Single-Acting Piston metering since material is dispensed in one action of the piston. This metering method is used in 1-Part Dispensing Systems and 2-Part Meter-Mix Dispense Systems.

Double Acting Piston Image

Double-Acting Piston

This continuous flow displacement metering method uses a upper ball-check piston on a rod and a lower ball-check in the inlet to dispense material. Fluid is loaded into the meter and dispensed from the cylinder on the up-stroke. Fluid is dispensed on the down-stroke. This is also called Dual-Acting metering since material is dispensed in both actions of the piston. This metering method is used in 1-Part Dispensing Systems and 2-Part Meter-Mix Dispense Systems.

Dual Reciprocating Piston Image

Dual Reciprocating Piston

This continuous flow metering method uses two dual-rod piston cylinders in tandem to dispense 2-part materials. Fluid is loaded into common sides of each cylinder and dispensed at the opposite end of the cylinder. At the end of the stroke valves reverse the flow. This meter operates by pressure from two Supply Pumps and feeds a 2-Part Dispense Valve.

Piston Cup Metering Image

Piston Cup Metering

This cup displacement metering method uses a piston cup on a rod to dispense material. Fluid is loaded into the meter when the piston retracts out of the cylinder. Fluid is dispensed when the piston enters the cylinder and displaces material. This is also called Single-Acting Piston Cup metering since material is dispensed in one action of the piston. This metering method is primarily used in 2-Part Meter-Mix Dispense Systems.

Precision Gear Metering Image

Precision Gear Metering

This continuous flow metering method uses two spur gears to dispense material. Material is supplied to the meter under pressure. The material flows around the perimeter of the gear housing. Material is sealed at the point where the gears mesh. Material is dispensed from the meter during rotation. This metering method is used in 1-Part Dispensing Systems and 2-Part Meter-Mix Dispense Systems.

Time and Pressure Metering Image

Time and Pressure Metering

This metering method uses a Material Regulator, Dispense Valve and Solenoid Valve with a timed controlled On-Off sequence to dispense a pre-set amount of material. The valve open time which determines the volume dispensed is controlled by a Time Delay Relay or automation program timer. The volume can be adjusted by varying the open time or the pressure. This metering method is typically used in 1-Part Dispensing Systems for mastic drop or potting applications.

Progressive Cavity Metering Image

Rotor/Stator Image

Progressive Cavity Metering

There are two basic styles of Progressive Cavity continuous flow Metering: Gerotor and Rotor/Stator. These metering methods are typically used in 1-Part Dispensing Systems for pumping or metering applications.

The Gerotor Progressive Cavity Meter uses a rotary motor and offset internal/external gear design to dispense material. Typically the external gear has one more tooth-cavity than the teeth of the offset rotary internal gear. At all times, the internal gear teeth contact and seal against the external gear internal surfaces to dispense material. This meter is ideal for pumping and metering low to medium viscosity fluids. The flow rate is adjusted by varying the motor RPM.

The Rotor/Stator Progressive Cavity Meter uses a rotary motor and intricate rod and cavity to dispense material. The rotor, a twisted rod, rotates inside the stator, an oval-shaped twisted cavity, to dispense material. This meter is ideal for pumping and metering high solids and high viscosity fluids. The flow rate is adjusted by varying the motor RPM.