Globe valves regulate flow in a pipeline. They are used to control or stop the flow of liquid or gas through a pipe. Globe valves are named for their spherical body shape with the two halves of the body being separated by an internal baffle. Although these valves exhibit slightly higher pressure drops than gate/ball valves, they may be used where the pressure drop through the valve is not a controlling factor.
It is comprised of a movable disk-type element and a stationary ring seat in a generally spherical body. The seat of a globe valve is in the middle of and parallel to the pipe, and the opening in the seat is closed off with a disk or plug. Globe valves can be structured to handle flow in either direction.
When the disc is fully lowered, the fluid supply is shut off. When the disc is fully raised, the fluid flow is at its maximum rate. In large industrial applications, a globe valve may be sealed using an electrical, pneumatic, or hydraulic actuator instead of a manual handwheel.
The baffle inside globe valves causes the product to divert its direction to move through the baffle. This angled movement means that the product cannot flow as freely and causes a pressure drop after the valve.
Because the entire system pressure exerted on the disc is transferred to the valve stem, the practical size limit for these valves is NPS 12 (DN 300). Globe valves larger than NPS 12 (DN 300) are an exception rather than the rule. Larger valves would require that enormous forces be exerted on the stem to open or close the valve under pressure. Globe valves in sizes up to NPS 48 (DN 1200) have been manufactured and used.
Globe valves are extensively employed to control flow. The range of flow control, pressure drop, and duty must be considered in the design of the valve to avert premature failure and to assure satisfactory service. Valves subjected to high-differential pressure-throttling service require specially designed valve trim.
Generally the maximum differential pressure across the valve disc should not exceed 20 percent of the maximum upstream pressure or 200 psi (1380 kPa), whichever is less. Valves with special trim may be designed for applications exceeding these differential pressure limits.
Typical applications of globe valves include: cooling water systems and fuel oil systems where flow needs to be regulated, high-point vents and low-point drains when watertightness and safety are major considerations, Feedwater, chemical feed, condenser air extraction and extraction drain systems, boiler vents and drains, main steam vents and drains, and heater drains, turbine seals and drains, turbine lube oil systems.
At MAGVALVES we supply forged steel globe valves up to 2” and casted globe valves from 2” and above.
Design: Straight Pattern, Y pattern, Angle type
Construction: Bolted Bonnet, Welded Bonnet, Pressure Seal – Ball, Plug, Needle, Parabolic, linear Disc
Main Design Codes: ASME B16.34, API602, BS5352, ISO 15761, BS1873, API 6A
Pressure Class: ANSI 150#-4500#
Size Range: from ½” to 24”
API 6A Pressure Class: 3000-15000
API 6A Size Range: from 1,13/16” to 11”
Ends: SW, NPT, BW, RF, RJ, HUB, Compact Flange
Material: Carbon steel, Stainless steel, Alloy steel
Alternative customized solutions can be provided including: design for cryogenic service /Bellow seal valves / Choke (adjustable and positive) / Blowdown valves (continuous and intermittent) / Quick opening / Self closing valves. Non rising handwheel globe valves / Screw down non return / DIN valves