cashco POSR-1 Посібник з монтажу, експлуатації та технічного обслуговування - Сторінка 2

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5. All installations should include a down stream

re lief device if the inlet pressure could ex ceed

the pressure rating of any downstream

equip ment or the maximum allowable outlet

pres sure rating of the unit.

6. Clean the piping of all foreign material in clud ing

chips, welding scale, oil, grease and dirt

before installing the regulator. Strainers are

recommended.

DO NOT HYDROSTATIC TEST THROUGH AN IN STALLED

UNIT, INCLUDING PILOT; ISOLATE BOTH PILOT AND MAIN

VALVE FROM TEST. The upper range spring pressure

level listed on the nameplate is the rec om mend ed "upper

op er a tive limit" for the sens ing diaphragm(s) in the pilot.

Higher pres sures could cause internal dam age. In addition,

note on the name plate that the Inlet and Outlet pressure

and tem per a ture rat ings are at different levels.

7. In placing thread sealant on pipe ends prior to

en gage ment, assure that excess material is

removed and not allowed to enter the reg u la tor

upon start-up.

8. Flow Direction. Install so the flow direction

match es the arrow cast on the body.

9. The POSR-1 comes factory piped between the

pilot supply and pilot loading. Install an external

sensing line from the 1/4" NPT con nec tion

opposite the factory piped pilot load ing port

III. PRIN CI PLE OF OPERATION

A. General:

1. The POSR-1 pilot obtains its operating

medium from the main valve body inlet.

Down stream pressure (P

un der side of the main valve's diaphragm and

the pilot valve's diaphragm(s).

2. The loading pressure on the top side of the

main valve's diaphragm is an intermediate

pressure higher than the downstream (P

pres sure by the sum of the pressures re quired

to overcome the main valve's plug unbalance

force and the piston spring's force.

3. The pilot has a bleed orifice that continuously

bleeds part of the loading medium down stream.

In op er a tion, the pilot valve's plug can flow

more medium than is bleeding down stream.

CAUTION

) registers on the

to a point downstream at gauge location; use

1/4" OD metal tubing for dis tanc es 4 ft (1.2 m)

or less, and 3/8" OD metal tubing (requires

1/4" x 3/8" tubing adapter) for distances

greater than 4 ft. (1.2 m). The sensing line

should always be sloped down ward so that

condensation will drain away from the pilot.

If regulator pipe line is ex pand ing to a larger

pipe line, always connect sens ing line to the

larger pipe line. NOTE: The POSR-1-20 does

not require a sensing line.

10. For best per for mance Cashco rec om mends

in stall ing regulator in a well drained horizontal

pipe, prop er ly trapped.

11. Recommended installation is with pilot valve

spring chamber vertical upwards. Orient such

that the spring chamber vent hole does not

collect rainwater or debris.

12. Regulators are not to be buried underground.

13. For insulated piping systems, rec om men da tion

is to not insulate regulator.

For welded installations, all internal trim parts, seals and

diaphragm(s) must be removed from reg u la tor body prior

to welding into pipeline. The heat of fusion welding will

dam age non-metallic parts if not re moved. NOTE: This

does not apply to units equipped with extended pipe

nip ples.

SECTION III

This increases the loading pres sure on

the main valve's plug and opens valve.

Partially closing the pilot valve's plug will

reduce its flow to less than the amount

bleed ing downstream, and allows the loading

pressure on the main valve's diaphragm to

de cay, allowing partial closing of the main

valve's plug. This continues until steady-state

is de vel oped.

4. The pilot valve's diaphragm(s) senses the

down stream (P

force generated to the force developed by the

)

pilot's range spring.

5. If, during operation, the downstream (P

pres sure falls below the pilot valve's setpoint,

the main valve's diaphragm senses the

reduced pres sure on its underside and instantly

moves down, increasing the flow through the

main valve. At the same time, the pilot valve

CAUTION

) pressure and compares the

IOM-POSR-1

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