cashco 987 Manual de instalación, uso y mantenimiento - Página 3

Navegue en línea o descargue pdf Manual de instalación, uso y mantenimiento para Unidad de control cashco 987. cashco 987 15 páginas. Globe-style pneumatic control valve body iom

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9. Flow Direction: Install so the flow direction

match es the arrow marked on the body.

10. For best performance, install in well drained

hor i zon tal pipe, properly trapped if a steam

service ap pli ca tion.

11. Valves are not to be direct buried un der ground.

12. Insulation may be applied as indicated in Figure

2. Drainage away from the packing area must

be ensured when fully installed, sealed and

lagged for outdoors installation.

13. Undue piping stress/strain or bending torques

may not be transmitted through the control

valve body. One pipe (inlet or outlet) should

be anchored rigidly for piping that is "hot" or

"cold" with respect to ambient temperature;

the re main ing pipe (inlet or outlet) should be

supported and guided to ensure uni di rec tion al

expansion/con trac tion.

C. Air Supply:

1. Use a desiccant dried, instrument quality air

supply. Such a supply is recommended for

outdoor installations, and is required in areas

of freezing weather conditions.

IV. STARTUP

A. General:

1. Ensure that the Model 987 unit has been

properly adjusted and calibrated, including

the positioner if installed.

2. Recommend startup to be in a "manual"

mode. This procedure assumes double block

(iso la tion) and bypass valves for the "control

valve station". See Figure 1.

3. Start with either of the two block valves closed,

with the other open. The bypass valve should

be closed. Pressurize system if possible/

prac ti cal.

4. Back out the airset's adjusting screw until

loose.

5. Turn on air supply pressure.

IOM-987

Limit of

Bonnet

Insulation

2. If air supply contains moisture and /or

lubricating oil, the air should be filtered with a

coalescing type of filter prior to use in stroking

the actuator.

3. Failure to remove moisture will cause corrosion

to the internals of the actuator casings.

4. Connections for the air supply are 1/4" female

NPT. Use a suitable pipe thread sealant when

installing the pipe or tube fitting. DO NOT

allow sealant to enter the tube/pipe.

SECTION IV

6. Adjust the air supply airset (filter-regulator)

to the proper level as indicated as follows:

7. Place loop controller into "manual" mode. Vary

setting from minimum – mid-range – max i mum

SIG output. Observe response of con trol

valve unit to these changes of input SIG. The

valve should fully stroke at the variation from

minimum SIG to maximum SIG; the mid-range

SIG should have the valve stem travel at/near

1/2 open.

DO NOT WALK AWAY AND LEAVE A MANUALLY

CONTROLLED CONTROL VALVE UNATTENDED!

Figure 2: Body Insulation

Bench Setting

Airset Output

psig

(Barg)

psig

5–15

(.34–1.0)

15–60

(1.0–4.1)

CAUTION

(Barg)

(1.4)

(5.2)