cashco 764PD Nstallation, Operation & Maintenance Manual

Browse online or download pdf Nstallation, Operation & Maintenance Manual for Controller cashco 764PD. cashco 764PD 14 pages. Pneumatic pressure controllers

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I. DESCRIPTION AND SCOPE

The Model 764P is a pressure controller used for sensing static pressure, and outputting a pneumatic signal

pro por tion al to the deviation from the setpoint.

The Model 764PD is a differential pressure controller used for sensing two static pressures ("HIGH" and "LOW"),

and outputting a pneumatic signal proportional to the deviation from the setpoint.

With proper materials selection, the units are suitable for gaseous, liquid or steam service. Refer to Tech ni cal Bulletin

764P-TB for design con di tions and selection rec om men da tions.

Use of oxygen gas as the IAS for a 764P or 764PD is outside the scope of this IOM, and is considered "special

construction".

Abbreviations Utilized:

CCW – Counter Clockwise

CW –

Clockwise

DIR – Direct

EXH – Exhaust

IAS –

Instrument Air Supply

II. INSTALLATION

1. A block valve of the globe/needle type should

be installed at the location of the pressure

tapping. Ball, butterfly or gate valves are not

rec om mend ed.

2. Recommended sensing tap pipe size is 1/2"

(DN15).

3. Location of pressure sensing tap should be

in a zone not subject to flow disturbances.

Rec om mend a min i mum of 10 pipe diameters

upstream and 10 pipe diameters down stream

from any elbow, tee, valve, etc. that disturbs flow.

4. A pressure gauge is recommended at the location

of each tapping. Differential pressure designs

may in cor po rate a differential pressure gauge.

5. A pigtail siphon is required for hot condensing

fluids, such as steam, to assure a liquid trap at

the controller. The siphon should be installed

as near to the pressure connection(s) on the

controller's diaphragm hous ing as practical.

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)

MODEL 764P & 764PD

PNEUMATIC PRESSURE CONTROLLERS

SECTION I

P1 –

Inlet Pressure

P2 –

Outlet Pressure

PB –

Proportional Band

PC –

Pressure Controller

PCV – Pres sure Control Valve

PI –

Pres sure Indicator

SECTION II

P/P –

REV – Rev o lu tion or Re verse

SIG –

SRV – Safe ty Relief Valve

TR –

V –

IAS @

60-100

Airset

psig

Supply

Port "B"

MODEL

764P

Port "A"

Supply @

EXH

SIG

LOAD

Supply

Blowdown - Drain

(Shaded portion for steam/condensate systems)

Figure 1: Recommended Piping Schematic for Pres sure

Reducing Control Valve with Positioner

IOM-764P / PD

Pneu mat ic-to-Pneu mat ic

Sig nal

Con den sate Trap

Vent

SRV

Pigtail

Siphon

REV

PROCESS

"Output"

PCV

P/P

DIR

Bypass

Blowdown - Drain

02-20

Outlet

@ P2