Dwyer VA User guide

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FLOWMETER INSTRUCTIONS
GENERAL INFORMATION
Inspect instrument for possible visible damage resulting from shipping. Notify UPS or other carrier as well as the distributor where the flowmeter was purchased of any claims.
Flowmeters always must be installed in a vertical position, any significant deviation from vertical will affect the readings.
CAUTION: Excessive tightening of valves may damage the orifice. It is important that all lines to be connected to the flowmeter are purged of
any dust or other residual contamination prior to installing the meter. All P and S style flowmeters are equipped with a filter in the inlet port. In some applications an additional filter should be installed at the inlet of the flowmeter.
STICKING FLOATS
Before installing open the valve of the flowmeter and check to make sure that the float or floats are moving freely in the flowtube. This is best done by slowly tilting the flowmeter from horizontal to vertical while observing if the float is rolling freely.
All meters are thoroughly inspected at the factory prior to shipping and are sealed in polyethylene bags to prevent dirt from entering into the flow passages. Certain small bore flowtubes have a clearance between the float and the inside walls of the flowtube of only a few ten thousandths of an inch. In some cases these flowtubes are found to have floats that are sluggish of not moving due to condensation resulting from temperature changes during shipping.
It is advisable to blow a dry clean gas through the meter to free float. SAFETY INFORMATION
P and S style flowmeters are designed to be operated at pressures not exceeding 200 psig (13.6 bars), or temperatures not exceeding 250 degrees F (121deg.C).
T style flowmeters are designed to be operated at pressures not exceeding 100 psig (6.8 bars), or temperatures not exceeding 150 degrees F (65.5deg.C).
NOTE: When using a T style Teflon flowmeter, at a pressure and/or temperature greater than standard the leak integrity approaches 1x10. Standard conditions are considered to be 14.7 psia (1 bar) and 70 degrees F (21deg.C).
All meters are factory tested for leakage prior to shipping. For hazardous fluids the flowmeter must be re-tested at the time of installation in the system, prior to usage. It is also important that a leak integrity test is performed periodically to maintain safe operating conditions.
Flowmeters must be protected from breakage due to external conditions such as objects bumping into or hitting the instrument, extreme vibrations, or attack by corrosive materials. It is the responsibility of the customer to acquaint the operator(s) of this flowmeter with all appropriate safety information.
VALVE ALIGNMENT
The built-in needle valve may be positioned at either the inlet or the outlet of the flowmeter. Valves are factory installed at the inlet of the f lowmeter unless otherwise requested.
APPLICATION VALVE POSITION Exhaust pressure at Valve at Inlet Atmospheric conditions Exhaust pressure other that Valve at Outlet Atmospheric conditions * Vacuum Valve at Outlet Liquid flow Valve at Inlet or Outlet
* When using a flowmeter with exhaust pressure greater than atmospheric conditions the standard calibrations can not be used. A calibration for the operating pressure must be obtained.
OPERATING INSTRUCTIONS
Close valve (if applicable) before initial use, then pressurize the system. Slowly open the valve until the float is at the desired flow rate. The flow
rate is read at the center of the float.
FLOWTUBE INSTALLATION OR REMOVAL
Remove the Front Shield and Back Plate. Do not remove the side panels from the flowmeter.
To remove the flowtube: P style meters: insert a 5/32” hex wrench into the Pressure Nut at the top
of the flowmeter. While holding the flowtube between your thumb and forefinger, turn the wrench counter clockwise to release the flowtube. Carefully remove the flowtube as not to damage it.
S and T style meters: insert a 3/32” diameter rod in the holes of the Lock Nut at the top of the flowtube. While holding the flowtube between your thumb and forefinger, turn the tool clockwise to release the flowtube. It may be necessary to push the Tube Adapter into the upper block to remove the flowtube.
To reinstall the flowtube reverse the above procedure. Take care to assure that the flowtube is centered, in the meter, at the top and bottom before tightening.
T style meters require additional tightening to insure proper sealing at the flowtube ends. The flowmeter should be tightened again 24 hours after the initial tightening.
A leak integrity test is recommended after disassembling any flowmeter.
FLOWTUBE CLEANING
If necessary, remove the flowtube from the frame as explained above, and clean as follows: Insert a plastic rod that will fit into the flowtube with no obstruction, into the bottom of the flowtube and push the retaining plugs and float out of the flowtube. Use tweezers to handle the float and store the float and the plugs in a lint free container. Before removing note the position of the plugs for reference when reassembling. Using a suitable solvent clean all the parts including the flowtube, dry them by means of a clean stream of air or gas.
To reassemble the flowtube use the push rod to first install the lower plug, next insert the float and then the upper plug.
Test by slowly tilting the flowtube from horizontal to vertical to assure that the float is moving freely. If the float is free follow the instructions above to reinstall the flowtube in the frame.
MAINTENANCE
Under normal operating conditions no special maintenance is required. Dirt or contamination may create problems within the flowtube by causing a restriction in the flow passage. Such conditions can be diagnosed by examining the flowtube. The most obvious indication of obstruction is the float being stuck in the flowtube. If the existence of the contamination is determined the condition may be rectified in a number of ways. The easiest being (if possible), to disconnect the inlet and the outlet of the flowmeter and purge the instrument by using a clean and dry stream of gas. The action of the float within the bore of the flowtube very often causes particle s to be dislodged through the outlet of the flowmeter.
TDV0102SM
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