User guide

ManualsBrandsCashco ManualsAccessories for water764PD Pressure Controller

Outlet

@ P2

Port “B”

IAS @

60-100

psig

MODEL

764P

Port “A”

EXH

REV

SIG

“Output”

LOAD

P/P

Blowdown - Drain

(Shaded portion for steam/condensate systems)

PCV

Bypass

II. INSTALLATION

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

installed at the location of the pressure tapping.

Ball, butterﬂ y 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 ﬂ ow 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 ﬂ ow.

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

ﬂ uids, 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 control-

ler’s diaphragm hous ing as practical.

Figure 1: Recommended Piping Schematic for Pres sure

Reducing Control Valve with Positioner

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 P1 – Inlet Pressure P/P – Pneu mat ic-to-Pneu mat ic

CW – Clockwise P2 – Outlet Pressure REV – Rev o lu tion or Re verse

DIR – Direct PB – Proportional Band SIG – Sig nal

EXH – Exhaust PC – Pressure Controller SRV – Safe ty Relief Valve

IAS – Instrument Air Supply PCV – Pres sure Control Valve TR – Con den sate Trap

PI – Pres sure Indicator V – Vent

SECTION I

MODEL 764P & 764PD

PNEUMATIC PRESSURE CONTROLLERS

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)

IOM-764P / PD

12-13

Supply

Supply @

DIR

Supply

Airset

SRV

PROCESS

Pigtail

Siphon

SECTION II

Summary of content (12 pages)

PAGE 1
IOM-764P / PD INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) 12-13 MODEL 764P & 764PD PNEUMATIC PRESSURE CONTROLLERS SECTION I I. DESCRIPTION AND SCOPE The Model 764P is a pressure controller used for sensing static pressure, and outputting a pneumatic signal proportional 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.
PAGE 2
6. It is recommended as a good practice to locate the controller as close as practical to the pressure tapping and at a similar elevation. For installations where the controller was factory mounted on a control valve unit, the pressure tapping should be within 6 - 10 feet (2 - 3 meters) of the control valve. (Remember to compensate for tappings located above the elevation of the controller for any liquid pressure head that may occur.) 7.
PAGE 3
Panel Mounted. Not factory provided. Requires field provision of a panel opening and support bracket per the below dimensions: Panel INSTALLED ASSEMBLY (Bottom View) #10-32 flat head machine screw and nut #10-32 machine screws Adjusting Screw PANEL CUTOUT (Front View) Countersink hole for #10-32 flat heat machine screw. Figure 6 Panel Mounted Assembly View 9. It is recommended that a 764PD be bracket or panel mounted. A 764PD can be pipe nipple mounted from 1/4" NPT connection. 10.
PAGE 4
SECTION III III. PRINCIPLE OF OPERATION 1. The 764 controllers employ laminar flow to produce the 3-15 psig (nominal 0.2–1.0 Barg) output signal. Lam i nar flow eliminates the need for range springs, levers, pivots and other parts that produce friction and lost motion. 5. Closing (CW rotation) the proportional band adjusting screw reduces the proportional band. Opening the screw increases the proportional band. 6.
PAGE 5
SECTION IV IV. STARTUP 1. Prior to pressurizing through the airset, disconnect the instrument air supply (IAS) at the airset inlet, open the IAS block valve and blow the piping clear of any debris. Reconnect the piping and open the isolation valve. Set the airset to 18 psig (1.2 Barg). 2. The unit is shipped with the proportional band (PB) set at a minimum value of approximately 3 percent.
PAGE 6
2. Remove cap screws (19) and nuts (18). Remove diaphragm upper case (13) and upper diaphragm O-ring (16). Remove diaphragm (12), and SST diaphragm cover (17) if supplied. Remove lower case diaphragm O-ring (16) and pusher post O-ring (23) for 764PD. Inspect for any corrosion damage and/or permanent deformation of the diaphragm (12) and diaphragm cover (17); if bent, replace. sub-assembly (2) end plate (2.2), and pull it outwards from the housing (1). Watch for the sensor pin (2.
PAGE 7
X = 1-27/32" (46.8mm) all ranges except 50–150 psig = 1-25/32" (45.2mm) X 5/16” The rounded end of the sensor plate (15) will touch the diaphragm (16) for the 764P, or the pusher post (24) of the 764PD. NOTE: The previous description is for 764PD’s and 764P’s in pressure ranges 2" - 30" Hg, 1-30 psig, 20-100 psig, 50-150 psig and 90-500 psig; it is also for 764PD’s for differential pressure ranges 1-30, 20-100 and 50-150 psid. Refer to Figure 12 “Diaphragm Sub-Assembly for 450-2500 psig”.
PAGE 8
SECTION VI VI. SHOP CALIBRATION 1. Install a 1/4" pipe plug in the “OUTPUT” port of unit. 5.1. FOR DIRECT ACTION: If the output pressure gauge is at/near 15 psig (1.03 Barg) increase the setpoint by rotating the adjusting screw (2.3) CW until the output decreases to 9 psig (0.62 Barg) If the output pressure gauge is at/near 0 psig (0.0 Barg) decrease the setpoint by rotating the adjusting screw (2.3) CCW until the output rises to 9 psig (0.62 Barg). 2. Provide an 18 psig (1.
PAGE 9
3. Erratic Operation; Rapid Cycling. Possible Cause A. Insufficient PB B. Improper air supply. C. Pulsing process sensing. D. Non-Correctible process dynamics. Remedy A. Increase PB in 1/8 rev. increments by turning the needle valve CCW. Reset setpoint as required (Max PB at 1-1/2 revs.). B1. Supply pressure too high. Reduce airset output supply pres sure to 15-18 psig. B2. Air supply unsteady. Replace airset. C1. Snub process needle valve as far as practical without shutting off.
PAGE 10
7. Cannot reach upper or lower pressure levels of stated range. Possible Cause Remedy A. Improper sensor sub-assembly setting. A. Remove sensor sub-assembly. Check dimension to those indicated in Figure 10. If dimension is correct, and high setting cannot be reached, decrease dim. "X" by rotating sensor end plate 1/2 revolution CW; reverse for lower setting. SECTION VIII VIII.
PAGE 11
Sensor Plate Sub-Assembly Sensor Plate Sub-Assembly 450-2500 psig Range Figure 12 Model 764P ITEM NO. 1 2 2.1 2.2 2.3 2.4 2.5 3 5 6 7 8 9 10 11 IOM-764P / PD DESCRIPTION Housing Sensor Sub-Assembly Sensor End Plate Adjusting Screw Sensor Pin Retsainer Clip Needle Valve O-Ring - Sensor O-Ring - Sensor Plate O-Ring - Needle Valve End Plate Screw Name Plate Screw Name Plate Gauge * * * * * ITEM NO. 12 13 14 15 15.1 15.2 15.3 15.4 16 17 18 19 20 Available Ranges psig (Barg) 1-30 (0.7-2.1) 20-100 (1.4-6.
PAGE 12
Available Ranges 1/4" NPT Tap 1-30 psid (.07-2.1 Bard) 20-100 psid (1.4-6.9 Bard) 50-150 psid (3.5-10.3 Bard) Figure 13 Model 764PD ITEM NO. 1 2 2.1 2.2 2.3 2.4 2.5 3 5 6 7 8 9 10 DESCRIPTION Housing Sensor Sub-Assembly Sensor End Plate Adjusting Screw Sensor Pin Retainer Clip Needle Valve O-Ring - Sensor O-Ring - Sensor Plate O-Ring - Needle Valve End Plate Screw Name Plate Screw Name Plate * * * * * ITEM NO.