Sand Probe Valve with Sensor – Axelson
The Sand Probe Valve with Sensor is a three-way block and bleed valve which detects the presence of abrasive material in a flowstream that could cause the piping to be cut out.
The valves shifts position when an abrasive gas or liquid erodes the sand probe sufficiently to allow flowline pressure to act against the sensor’s lower stem. The Sand Probe instrument pressure working range is from 0 to 250 psi with 1/4″ NPT connections.
The section attached to the flow line has a working pressure range of 100 to 10,000 psi and has a 1/2″ 14 NPT mounting connection with a 1/4″ female port for connecting the probe.
TECHNICAL DATA:
Input from Sand Probe – 100 – 10,000 psi
Control Supply – 0 – 250 psi
Overall Length – 5-3/4″
Diameter – 1-3/4″
Material: 303 Series Stainless Steel
Seals – Buna-N or Viton
Weight – 1.75 lbs.
HOW TO ORDER THE SAND PROBE SENSOR:
PN: 41215-002 – Stainless Steel Trim with Buna-N Seals – 303 SS Upper Body
PN: 41215-004 – Stainless Steel Trim with Viton Seals – 303 SS Upper Body
OPERATION
The Sand Probe Sensor is installed at any point in a flow line to detect the affects of abrasive fluid flow. The Sand Probe provides a manual override to shut in the safety system which also acts as an indicator. The knob is normally in a down position. This allows instrument pressure to pass from port A to port B of the sand probe sensor. The sand probe sensor will remain in its open position until abrasive erosion cuts through the sand probe and admits flowline pressure to the sand probe sensor’s lower stem. Line pressure acting against this sand probe sensor’s stem are forces the stem upward.
Flowline pressure is sealed from atmosphere by the lower o-ring, and the metal-to-metal seal is affected between the lower stem, and lower body or sensor stop. Once the lower stem moves up in its sealing position, the three-way block and bleed valve of the main sensor body shifts to block instrument air at port A and back bleeds instrument pressure from port B to port D. This causes downstream safety shut-in components to react to close the SSV safety valve. The sand probe will remain in a locked-out block and bleed position until the sand probe is replaced. The sand probe cannot be overridden and placed back into service with flowline pressure applied to the lower stem. In normal condition (good probe) the three-way block and bleed valve of the sand probe can be pulled out to manually shut in the system but must be pushed downward to its in-service position to reactivate and open the SSV safety-valve.
The Degree of Sand Erosion in a pipeline depends on:
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Flow Velocity
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Sand Content
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Fluid Composition
To determine the best location for a sand erosion probe, there are things to be considered:
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The probe must be located in the area of HIGH FLOW VELOCITY. Many devices such as valves, chokes, and turns may create turbulence which causes high velocity impact and erosion on one side of a pipe while virtually no erosion may occur on the opposite side of the pipe.
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Consider what is to be protected by a probe. A probe may be used to protect a pipeline with elbows and turns where constant size is maintained, however, a probe in this type of line may not detect erosion in the area of any restriction, (reduced bore valve, meter run).
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The material of the probe should e equivalent or weaker in erosion properties as compared with the pipeline. Preferably the probe material should be the same as the material being protected, yet with much thinner wall sections.
Erosion Probe Failure
When an erosion probe fails due to erosion, flow line pressure is admitted to a sensing device which actuates controls, alarms, or indicators. The probe failure indicated that erosion has occurred in the line. This should be interpreted that erosion is occurring and testing and inspection required. There is no direct correlation between probe erosion depth and pipeline erosion depth. The amount of erosion in the pipeline must be determined by additional inspection methods.
REMEMBER – The sand probe indicates that sand erosion is occurring. The sand probe does not protect the pipeline or equipment.
HOW TO ORDER THE SAND PROBE – PN: 41242
See chart for Suffix to determine probe size.
41241-XXX
Example: 41242-117
303 S.S. 1-3/4″ probe
