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PA Series Air Pilots

PA Pilot

The PA Air-Loaded Pressure Pilot is used with the HD Regulator to control steam pressure on steam mains and process equipment. The principal advantage the PA-Air Pilot has over standard spring-loaded pilots is that pressure adjustments to the regulator can be made from a remote location. A regulator that is located in a difficult to reach or inaccessible location can be adjusted by a remote control panel board.

How It Works
When air pressure is applied to the upper chamber of the air pilot it exerts a downward force on the air pilot’s diaphragm. This force controls the outlet pressure of the steam through the regulating valve. The control process is similar to a spring loaded pressure pilot except that the air pressure takes the place of the spring. There are three separate models of air pilots that make up the complete range depending on the steam pressure that needs to be controlled and the control air pressure available. See Pressure Adjusting Ranges chart.

Features
  • Pressure adjustments to the regulator can be done from a remote location using an air signal
  • Air-operated pilot ensures instant response and extremely accurate control
  • Full port strainer and blowdown valve on pilot adapter for protection of pilot from dirt and scale
  • Controls pressure settings within ±1 PSIG

Description of Operation

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.



Remote Control Panel Boards

Three different remote control panel boards can be used along with the Air Pilots. Supply air is fed directly through the control panel board to the air pilot. You can choose one of the three options of control panel boards when using the air piloted regulators. Minimum of 5 PSIG air supply pressure is required

The PL1 is made up of an air pressure regulator with adjustment knob and pressure gauge that measures the amount of air pressure going to the pilot (air signal). Steam pressure of the system is controlled by adjusting the air pressure regulator.

The PL2 is the same as the PL1 with the addition of an extra air pressure gauge for measuring the air supply pressure to the control panel board.

The PL3 is the same as the PL2 with the addition of a Steam Pressure Gauge for measuring steam pressure on the outlet side of the regulating valve.



How PA Air-Loaded Pressure Pilots Work

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.

Pilot Operation

When air pressure is applied to the upper chamber of the air pilot, it exerts a downward force on the air pilot’s diaphragm. The lower chamber of the air pilot is connected to the outlet side of the regulator using a sensing line. The purpose of the sensing line is to sense the pressure on the outlet side of the regulator and direct it under the lower pilot diaphragm to push it upwards. When the intended set pressure is reached, the pilot valve closes, which then closes off the flow path of steam to the underside of the diaphragm chamber in the regulator body. The regulator modulates open and closed maintaining the desired downstream pressure. To change downstream pressure, increase or decrease air pressure to pilot accordingly

PA Series Air Pilots

The HD Regulator with the Air Pilot is used for reducing steam pressure on steam mains and process equipment. The “PA” Air Pilot can also be used in conjunction with the PTL and PTR Pneumatic Temperature Controllers for controlling temperature in process applications. The principal advantage of the “PA” Air Pilot over standard spring-loaded pilots is that pressure adjustments to the regulator can be made from a remote location. A regulator placed in a difficult to reach or inaccessible location can be adjusted by a remote control panel board placed in an accessible location.

ModelReduced Pressure Range (psig)Ratio of Outlet Pressure to Control Air PressureWeight (lbs)
PA-13 - 1251:115
PA-43 - 2004:119
PA-13 - 1251:115
Downloads
Catalog Spec Sheet (pdf)
I&M (pdf)
I&M (pdf) - Quick Install
Product Overview
The PA Air-Loaded Pressure Pilot is used with the HD Regulator to control steam pressure on steam mains and process equipment. The principal advantage the PA-Air Pilot has over standard spring-loaded pilots is that pressure adjustments to the regulator can be made from a remote location. A regulator that is located in a difficult to reach or inaccessible location can be adjusted by a remote control panel board. The PA-Air Pilot can also be used in conjunction with the PTL or PTR pneumatic temperature controllers for controlling temperature in process applications.
Features
• Pressure adjustments to the regulator can be done from a remote location using an air signal
• Air-operated pilot ensures instant response and extremely accurate control
• Full port strainer and blowdown valve on pilot adapter for protection of pilot from dirt and scale
• Controls pressure settings within ±1 PSIG
How It Works
When air pressure is applied to the upper chamber of the air pilot it exerts a downward force on the air pilot’s diaphragm. This force controls the outlet pressure of the steam through the regulating valve. The control process is similar to a spring loaded pressure pilot except that the air pressure takes the place of the spring. There are three separate models of air pilots that make up the complete range depending on the steam pressure that needs to be controlled and the control air pressure available. Maximum control air pressure on air pilots is 125 PSIG.The larger Diaphragm area of the PA4 & PA6 Air Pilots allow the use of lower control air pressure to regulate higher pressure steam.

See Pressure Adjusting Ranges chart.

 

Selection / Sizing / Capacities
PA - AIR PILOT
Specify:
• Air Pilot PA1, PA4 or PA6
• Remote Control Panel Board (PL1, PL2 or PL3)

Example:
The PA-Air Pilot is being used in conjunction with the PL2 Control Panel Board( PL Accessory) 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.

REGULATOR BODY
Specify:
• HD regulator body
• Regulator size or capacity and pressure range of steam required
• End connections (threaded, 150/300# flanged)

Dimension and Weights