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
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
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
To determine the best location for a sand
erosion probe, there are things to be considered:
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
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).
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
Erosion Probe Failure
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.
- The sand probe indicates that sand erosion is
occurring. The sand probe does not protect the pipeline or
HOW TO ORDERTHESAND PROBE - PN: 41242
See Chart Below for Suffix
to determine probe size.
303 S.S. 1-3/4" probe
P.C. McKenzie Company P.O. Box 112638 Pittsburgh, PA 15241