AXELSON ESP Pilot

- High Low Pressure Sensor

The Axelson ESP Pressure Sensor is a highly accurate and reliable device designed to detect an abnormal operating condition in a safety system and transmit a signal to perform a specific shutdown function. The Pressure Sensor or pilot is a 3-way block and bleed valve that is controlled by a piston and spring. It is used to sense predetermined pressure and, when that pressure is reached, shift the 3-way valve. The actuation point is easy to adjust by turning the adjustment cap. This changes the spring force. Turning the cap clockwise will increase the pressure setting. Turning the cap counter clockwise will decrease the pressure setting.

The sensor may be used to detect high pressure or a low-pressure conditions by connecting the input instrument pressure to the appropriate port. When connected to either port the remaining port becomes the exhaust port.

ESP Programmed as a LOW PSL Pilot Instrument pressure is connected to the port stenciled “LO.” The port stenciled “OUT” is connected to downstream safety components. The port stenciled “HI” acts as an exhaust port. The spring applies a downward force against the stem holding the pilot in a block and bleed position. Line pressure at Port D acts against the lower piston to create an upward force. Once the upward force exceeds the downward force of the spring, the stem will move upward opening the LO Port to the OUT Port to actuate downstream safety components. The pilot will remain in an open position until pressure at Port D drops below the low pressure setting of the pilot.

ESP Programmed as a HIGH PSH Pilot Instrument pressure is connected to the port stenciled HI and the port stenciled OUT to downstream safety components with the LO Port acting as an exhaust. With flowline pressure below the high pressure set point of the pilot, the HI Port is open to the OUT Port, allowing instrument pressure to pass to downstream safety components. The spring will hold the pilot in an open position until flowline pressure activating the pilot piston exceeds the downward force of the spring. Once line pressure at Port D increases above the set point, the stem is forced upward, blocking instrument pressure at the HI Port and back bleeding instrument pressure through the OUT Port to the LO Port, causing the safety system to react. The pilot will remain in a block and bleed position until flowline pressure drops below high pressure set point.

The schematic illustrates a typical high-low safety shut-in system that uses an Axelson DG-3 diaphragmoperated gate valve, a pair of highlow sensors, and a PRV relay.

Two Pilots can be connected in a series and used for both high and low sensing. The combination high and low pilot is called the ESPHL.

ESP PRESSURE SENSOR SENSING RANGES & PART NUMBERS: BASE NUMBER - 41046-XXX (Standard Body)

EXAMPLE: 41046-211

High Flow Body - 41046-XXX3 (use 3 to indicate high flow) Example:

41046-2113

Sensing Pressure Maximum W.P. Range

Sensing Unit & Spring

PART NUMBER

0.25 - 5.3 PSI

250 PSI

4" Diaphragm w/Ultra Light White Spring

41046-258

0.5 - 20 PSI

250 PSI

4" Diaphragm w/Light Orange Spring

41046-218

1 - 40 PSI

250 PSI

4" Diaphragm w/Heavy Blue Spring

41046-228

0.5 - 20 PSI

250 PSI

2" Diaphragm w/Ultra Light White Spring

41046-256

1 - 100 PSI

250 PSI

2" Diaphragm w/ Light Orange Spring

41046-216

2 - 200 PSI

250 PSI

2" Diaphragm w/ Heavy Blue Spring

41046-226

1 - 60 PSI

10,000 PSI

1-1/8" Piston w/Ultra Light White Spring

41046-251

10 - 125 PSI

10,000 PSI

1-1/8" Piston w/Light Orange Spring

41046-211

75 - 550 PSI

10,000 PSI

1-1/8" Piston w/Heavy Blue Spring

41046-221

300 - 1,000 PSI

15,000 PSI

1/2" Piston w/Light Orange Spring

41046-212

500 - 2,000 PSI

15,000 PSI

1/2" Piston w/Heavy Blue Spring

41046-222

1,900 - 5,000 PSI

15,000 PSI

1/4" Piston w/Light Orange Spring

41046-213

4,900 - 10,000 PSI 15,000 PSI

1/4" Piston w/Heavy Blue Spring

41046-223

10,000 - 20,000 PSI

3/16" Piston with Heavy Blue Spring

41046-224

20,000 PSI

HIGH FLOW ESP: The ESP Sensor is also available with a high flow rate. The High Flow Rate Body provides increased flow capacity and increased pressure capacity through the instrument ports. This allows the sensor to be used as a block and bleed valve with faster reaction times for the system. It may also be used as a 2-way valve on a bleed only system. Instrument Pressure - 600 psi Maximum

BASIC INFORMATION: Instrument Pressure Range Standard Body ............. 200 psi max. High Flow Rate Body ...... 600 psi max. NOTE: When using a urethane o-ring on the stem - 1,480 psi maximum instrument pressure. Repeatability to Set Point within 3% of set point Cv Factor (Flow Capacity) Standard body ........ 0.028 High Flow Rate Body ..... 0.058

Dead Band (Spread) ......................... Percent of Range 1 1/8, 1/2, 1/4 in. Pistons ................ 5% Diaphragm Types ............................... 3% 3/16 in Piston .................................... 10%

AXELSON ESP SPRING COLOR CHART: ULTRA LIGHT - WHITE SPRING LIGHT - ORANGE SPRING HEAVY - BLUE SPRING

RECOMMENDED PREVENTATIVE MAINTENANCE FOR THE ESP SENSOR: (1) Cycle Test once a month or more often if service dictates. (2) Disassemble, inspect all parts, and replace O-rings annually or more often if service dictates. TO ORDER ORING KITS ESPVITONKIT - Viton O-ring Kit ESPBUNAKIT - Buna O-ring Kit Urethane O-ring needs to be specified and can be added to the kit. (3) To change spring: with flow line pressure at port D, loosed locknut and remove the cap. Replace spring and reassembly. (See spring part numbers below.) Spring Part No: (2nd Digit) 41047 - Light-Steel Spring (Orange)

41048 41049 41050 46301

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Heavy-Steel Spring (Blue) Light-Inconel Spring (Yellow) Heavy- Inconel Spring (Green) Ultra-Light-Steel Spring (White)