HVAC Control Valves: Globe Valves, Zone Valves, Motorized Ball Valves, Solenoid Valves & Butterfly Valves
Control valves serve a large variety of needs in HVAC automatic temperature control systems. Control valves come in a wide assortment of shapes and sizes, and can be controlled in many ways. NECC stocks valve actuators and linkages separately that can be used to put together over 30,000 combinations of different valve assemblies. Here are some descriptions to help narrow your search, and help you find exactly what you need.
In order to purchase a new or replacement valve body or assembly, you need to have the following specifications available:
Valve pipe size and Cv (flow capacity). Don’t always assume the valve you are replacing was originally specified correctly. Many are oversized and don’t control accurately.
Valve body connection & pattern -screwed connection, flanged valves, union connection, half union valves, flared valves, sweat connections, 2 way valves, 3 way valves, straight valves, angle valves, mixing valves, diverting valves, normally open valves and normally closed valves.
Globe Valves - This is the widest and most available type of control valve. There are more body styles and actuators than any other valve style. Globe valves are normally available from ½” to 6” Sizes. Brass, iron and steel.
Solenoid Valves - The simplest and easiest to apply for a variety of on-off uses at an economical cost. Solenoid valves are available in many sizes, voltages body patterns and materials (brass, stainless, etc.). They are usually used in applications under 2”. Above that, the cost and close-off pressures keep solenoid valves from being the best choice.
Butterfly Valves - Typically used for on-off control of larger flows at a reasonable cost. Butterfly valves are usually not suited for close regulation of fluid flow. Butterfly valves come in the largest sizes available (up to 24”). Because of their rotary action, the amount of torque required for close-off butterfly valves is lower than other valve types. 2-way, 3 way mixing and diverting models available.
Ball Valves - A low cost way to control flow. Because of their rotary action ball valves require less torque to operate. Originally applied for on-off service, ball valves didn’t have very good flow regulation. With the advent of characterized guides and custom ball cuts, ball valves are quickly replacing smaller globe valves in new construction projects.
Zone Valves - Very popular valves for low pressure control of fan-coil units, radiators and small zones. Zone valves are typically available in sizes from ½” to 1½”, with flared, sweat or threaded connections. On-off, modulating, pneumatic control. Straight, angle, 2 way 3 way. Zone valves' compact size makes them a popular choice in tight situations.
Non-Electric Valves - These models don’t require electricity and work on pressure or temperature. The main types are: thermostatic radiator valves, refrigeration control valves, remote bulb thermostatic valves, pressure activated valves among others. For thermostatic valves, you need to pre-select the thermal range that fits your set point. The range cannot be changed on site.
Industrial Valves - Many special applications require high performance that only an industrial grade valve can provide. High pressure control valves for tall buildings, high pressure steam mains, corrosive liquids, (brine, sea water, industrial cooling liquids, etc.), special body requirements-stainless steel valves and more.