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Select from a standard Main Valve or Low Pressure Main Valve depending on the steam pressure range.
Inlet Pressure Range:15-300 PSIG - Standard Main Valve5-20 PSIG - Low-Pressure Main Valve
Minimum Differential Pressure*: 10 PSIG - Standard Main Valve 3 PSIG - Low-Pressure Main Valve
Valves are sized according to the application - By choosing a larger valve than required to accommodate existing piping size, the regulator may overshoot which leads to erratic pressure or temperature control often referred to as “hunting”. Using the Reduced Valve Port allows you to size a larger valve than required while maintaining the correct sizing.
Stainless Diaphragm OptionThe HD regulator is supplied standard with a high tensile strength Phosphor Bronze diaphragm which has been determined thru experience and testing to be the absolute best diaphragm material choice for steam applications. Stainless Steel diaphragms are offered as an option because certain industry specifications have been written requiring stainless steel. Note: Stainless steel is prone to work hardening and will not last as long as phosphor bronze; only use if required by the specification to do so.
Stainless Steel External TubingCopper tubing is supplied as standard. Copper tubing offers excellent corrosion resistance and is easy to bend and manipulate and normally outlasts the life span of the valve. Stainless Steel tubing is offered as an option.
HD Main Valve Selection
The HD-Series Pilot-Operated Regulators is for pressure reduction or temperature control in steam service applications. These valves require the use of a pressure or temperature pilot which attaches to the main valve to perform the desired function. Back pressure and differential pressure pilots are also available. When both a pressure and temperature pilot are used together an additional pilot adapter is required.
These Model Codes are for HD Main Valve ONLY, control Pilot must be ordered separately.
Ordering Instruction:
Example Model Codes for Main Valve:
Stainless Diaphragm Option
The HD regulator is supplied standard with a high tensile strength Phosphor Bronze diaphragm which has been determined thru experience and testing to be the absolute best diaphragm material choice for steam applications. Stainless Steel diaphragms are offered as an option because certain industry specifications have been written requiring stainless steel. Note: Stainless steel is prone to work hardening and will not last as long as phosphor bronze; only use if required by the specification to do so.
Stainless Tubing Option
Copper tubing is supplied as standard. Copper tubing offers excellent corrosion resistance and is easy to bend and manipulate and normally outlasts the life span of the valve. Stainless Steel tubing is offered as an option.
Reduced port trim Option
Regulators should be sized to meet the application not to fit the pipe size. Over sizing a regulator may cause overshoot which leads to erratic pressure or temperature control often referred to as “hunting.” A valve with reduced port trim has a reduced seat and disc size for a given pipe size, (refer to capacity charts)
Low Pressure (Differential and inlet) Option
Regulators require a minimum Inlet pressure as well as a minimum pressure drop across the valve to operate properly. The HD Standard Main valve requires a minimum inlet pressure of 15 PSIG and minimum differential pressure of 10 PSI. The Low Pressure Main valve requires 5 PSIG minimum inlet pressure and 3 PSI minimum differential pressure. Low pressure main valve uses a EPDM diaphragm.
Reducing Pressure
Several choices of pilot valves can be used for pressure reduction on steam applications. The opening of the pressure pilot controls the operation of the Main Valve. The PP & PP5 are referred to as spring loaded pressure pilots because an adjustable control spring is used to apply the opening force to the pilot valve. Pressure adjustment screw is located on top of pressure pilot. The PA pilot is referred to as an Air Loaded pressure pilot because Air Pressure is used to apply the opening force to the pilot valve. The PA air-loaded pilot allows for convenient and remote adjustment of steam pressure using a small air regulator.
Controlling Temperature
When steam is required for a heating applications, a temperature pilot is used. The PT pilot (most common) is referred to as a “solid liquid fill” and contains a temperature probe connected by a length of capillary tubing to a bellows in the pilot valve. When the temperature bulb is heated the liquid inside the probe expands the bellows and closes off the pilot valve. PTRP pilot operates in a similar fashion except this style is referred to as a vapor tension unit.
Controlling Temperature & Limiting Maximum Pressure
The PT & PP Pilot combination is used when it’s required to control temperature while limiting downstream pressure to a maximum value. The downstream pressure is limited to a maximum setting by the pressure pilot, while the temperature pilot maintains the correct temperature of the process.
Remote Pressure Controlled
The PA-Air Pilot is being used in conjunction with the PL2 Control Panel Board to regulate steam pressure. A small air regulator on the panel board can be adjusted to control the air pressure to the pilot. One gauge on the panel board measures air line pressure to the panel board and the other gauge shows the air pressure being sent to the pilot. Steam pressure at the outlet of the regulator is controlled by the air pressure signal to the pilot. Depending on the air pilot model chosen (PA1, PA4, PA6), there will be a 1:1, 4:1, or 6:1 ratio of outlet steam pressure to air pressure.
Combination Pilots
The HD-Series Steam regulating valve can be used with up to three pilots simultaneously to control the operation of the valve. An example is when steam i s used to heat water in a Heat Exchanger. The Temperature Pilot will maintain precise control of outlet water temperature by controlling the amount of steam flow through the valve while a Pressure Pilot limits the maximum outlet steam pressure of the regulator to the Heat exchanger. A third pilot (Solenoid pilot) can be added to electrically activate or de-activate the system.
On/Off Operation
Electrical On-off control of the regulator is possible by using the PS-Solenoid Pilot. The PS-Pilot allows the regulator to be shut off or turned on electrically. Normally the regulator is equipped with either a PP-Pressure Pilot or PT-Temperature Pilot in addition to the PS-Solenoid Pilot.
Differential Pressure
The PDP-Pilot is used when trying to balance two different media sources that are being blended.
HD Main Valve Features
The HD Series Pilot-Operated Regulating Valve was designed for extremely accurate control of temperature and pressure in steam service applications. The HD Series is made of Ductile Iron for extended pressure and temperature ratings when compared to cast iron. The Standard Main Valve is used for an inlet steam pressure range of 15-300 PSIG. The Low-pressure Main Valve contains a different main valve spring and is available for an inlet pressure range of 5-20 PSIG.
Features of the HD Regulating Valve
Pilot Adapter
The pilot adapter includes a full port strainer and blowdown valve for ultimate protection against dirt and scale, as well as more efficient start-ups. The innovative design allows the pilot to be mounted on either side of the regulator and is easily field-reversible without having to re-bend tubing. Pilots are easily installed on the pilot adapter using only 4 bolts – no tubing connections to the main valve are required to be made in the feild.
Seat & Disk
Hardened stainless steel trim (55 Rc) for extended life even in the most demanding applications.
Low Pressure & High Sensitivity
The HD Series Pilot-Operated Regulating Valve was designed for extremely accurate control of temperature and pressure in steam service applications. The HD-Series is made of Ductile Iron for extended pressure and temperature ratings. These regulators use several different control pilots which are mounted to the valve to control pressure, temperature or a combination of both. When two or more pilots are used at the same time - for example, both a pressure and a temperature pilot - an additional pilot adapter for the second pilot is required (must indicate when ordering).
Description
Reduced Port Valves.
Stainless Steel Diaphragm
Stainless Steel External Tubing.
Required when 2 or more pilots are sued on the same valve (not required for Solenoid pilot)