20.08.2015   Handbook Nuclear Terms

Calibration Standards

Whether the sensor has readout capability or not, its proper calibration involves subjecting it to precise pressures

CONNECTING TUBING NOTES

Подпись: TRANSMITTER A CONNECTING LINE SHOULD BE AS SHORT AS IS PRACTICAL EQUIVALENT VERTICAL HEAD (VERTICAL DISTANCE BETWEEN PRESSURE SOURCE AND TRANSMITTER) IN PSIG MUST BE LESS THAN 20% OF RANGE OF TRANSMITTER

В DO NOT ANCHOR TUBE SO TIGHT THAT IT CANNOT EXPAND DURING BLOWDOWN

Подпись: ALTERNATE INSTALLATION WITH SNUBBER
Подпись: RECOMMENDED INSTALLATION

C USE PRESSURE SNUBBER FOR ALL WATER FLOW GAS FLOW HIGH PRESSURE (1500 PSIG OR ABOVE) HIGH VELOCITY STEAM FLOW ANY FLOW WHERE A PUMP IS USED OR WHEREVER RAPID PRESSURE OSCILLATIONS ARE ANTICIPATED

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ITEM

MATERIAL

1

1 /2—1N, 3/4-1N, OR 1-IN WELDING ADAPTER, SIZE DEPENDING ON SIZE OF NIPPLE ITEM 2

2

1 /2-IN NIPPLE FOR SERVICE UP TO 900 PSIG OR 800°F 3/1HN NIPPlI}F0R service 901 PSIG 0R 801°F 0B HIGHER

3

1 /2-IN, 3/4-IN, OR 1-IN GLOBE VALVE, SUITABLE FOR MAXIMUM SFRVICE PRESSURE AND TEMPERATURE, SIZE DEPENDING ON SIZE OF NIPPLE, ITEM 2

4

FITTING OR BUSHING IF REQUIRED SIZE DEPENDING ON SIZES OF VALVE ITEM 3 TUBING, ITEM 6

5

ANCHORING CLIP OR OTHER DEVICE

6

TUBING, WITH NECESSARY FITTINGS

1/2-IN 0 D TUBING OR 3/8-IN PIPE (OR LARGER) FOR SERVICE UP TO 1500 PSIG 5/8-IN 0 D TUBING OR 1/2-IN PIPE (OR LARGER) FOR SERVICE 1501 PSIG OR HIGHER

7

REDUCING TEE 1 /4-IN OUTLET TO INSTRUMENT, SIZE OF STRAIGHT-THRU SECTION DEPENDING ON SIZE OF TUBING ITEM 6

8

GLOBE NEEDLE VALVE SUITABLE FOR MAXIMUM SERVICE PRESSURE AND TEMPERATURE SIZE DEPENDING ON SIZE OF TUBING ITEM 6

9

1 /4—1N STEEL NIPPLE, LENGTH AS REQUIRED

10

t/4-IN GLOBE NEEDLE VALVE, SUITABLE FOR MAXIMUM SERVICE PRESSURE AT 100°F

11

1 /4—1N STEEL TEE AND PLUG

12

FLEXIBLETUBINGCONNECTOR. PT NO 681853A1 18-IN-LONG STAINLESS STEEL TUBING WITH 1/4-IN MALE CONNECTORS AT EACH END SUITABLE FOR 5000 PSIG AT 100 F

13

STEEL BUSHING, IF REQUIRED, DEPENDING ON SIZE OF SNUBBER ITEM 14

14

1/4-IN OR 1/2-IN PRESSURE SNUBBER ASCROFT OR EQUAL

ALL SIZES AND MATERIALS LISTED CONFORM TO THE LATEST REVISION OF THE CODE FOR PRESSURE PIPING ASA B31 1 WHERE MATERIALS ARE NOT NOTED OR WHERE DIFFERENT FITTINGS ARE TO BE USED ALWAYS SELECT MATERIALS THAT CONFORM TO SAID CODE DO NOT CHANGE ANY SIZE TO ONE WHICH WILL NOT MEET THE CODE

Fig. 4.22—Recommended connecting tubing or piping for pressure transmitters. (Courtesy Bailey Meter Company)

and reading out on accurate gages. Correct readout volt­meters, ammeters for use with component signal con­ditioners, and other necessary accessories are recommended by the various manufacturers. Equipment for developing pressure varies according to the magnitude of the desired pressure.

For very low pressures, water, oil, and mercury manom­eters can be used. The bore should be large enough to provide an accurate column reading of the deflection scale. Air pressure from a compressor or a vacuum-pump source is also needed for a complete setup.

For medium pressures, transfer gages having calibration traceable to the U. S. Bureau of Standards can be used. Where water is used in the gage, the readings must be corrected for the weight of water unbalance between the sensor and the master gage.

For high pressures, a deadweight tester must be used. These are available for pressures from 15 to 10,000 psi. Constructed of stainless steel, using distilled water, and including a self-contained hand pump, the deadweight tester is an important calibrating device and may be used to calibrate master transfer gages for medium-pressure work.

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