Manual

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I. DESCRIPTION AND SCOPE

The Model BQ is a back pressure relief regulator used to control upstream (inlet or P

) pressure. Side inlet and ﬂ ow-thru

connections are 1/4", 3/8", and 1/2" NPT (DN8, DN10, DN15); outlet (bottom discharge) connection is always 1/2" NPT (DN15).

With proper trim utilization, the unit is suitable for liquid, gaseous, or steam service. Refer to Technical Bulletin BQ-TB for design

conditions and selection rec om men da tions.

MODEL BQ

BACK PRESSURE / RELIEF REG U LA TOR

II. INSTALLATION

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)

IOM-BQ

12-13

6. Clean the piping of all foreign material including chips,

welding scale, oil, grease and dirt before installing the

regulator. Strainers are recommended.

7. In placing thread sealant on pipe ends prior to en-

gage ment, ensure that excess material is removed

and not allowed to enter the regulator upon startup.

8. Flow Direction: Install so the ﬂ ow direction matches

the arrow cast on the body. Connect the inlet pressure

to the body side connection(s). Fluid will relieve out of

the bottom connection. The double inlet connections

are for in-line installation (plug one side connection if

in-line installation is not required).

9. Regulator may be installed in a vertical or horizontal

pipe. If it is a steam system, ensure the piping is properly

trapped and vented.

CAUTION

This is not a safety device and must not be substituted for a code approved pressure safety relief valve or a rupture disc.

SECTION II

SECTION I

WARNING

The maximum inlet pressure is equal to 1.5 times the larger

number of the stated range spring on the name plate, and is

the recommended “upper operative limit” for the sens ing

di a phragm. Higher pressures could damage the di a phragm.

(Field hy dro stat ic tests fre quent ly destroy di a phragms.

DO NOT HY DRO STAT IC TEST THRU AN IN STALLED UNIT;

ISOLATE FROM TEST.)

CAUTION

Installation of adequate overpressure pro tec tion is rec-

ommended to pro tect the reg u la tor from overpressure

and all down stream equip ment from damage in the event

of regulator failure.

1. An inlet block valve should always be installed.

2. If service application is continuous such that shutdown

is not readily accomplished, it is recommended that

an inlet block valve, outlet block valve, and a manual

bypass valve be installed.

3. Pipe unions should be installed to allow removal from

piping.

4. An inlet pressure gauge should be located ap prox i mate ly

ten pipe diameters upstream and within sight. An outlet

pressure gauge is optional.

5. All installations should include an upstream relief de vice

if the inlet pressure could exceed the pressure rating of

any equipment or the maximum inlet pres sure rating of

the unit.

CAUTION

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.

Recommended piping schematic for Back Pressure Regulator

Summary of content (8 pages)

PAGE 1
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-BQ 12-13 MODEL BQ BACK PRESSURE / RELIEF REGULATOR SECTION I I. DESCRIPTION AND SCOPE The Model BQ is a back pressure relief regulator used to control upstream (inlet or P1) pressure. Side inlet and flow-thru connections are 1/4", 3/8", and 1/2" NPT (DN8, DN10, DN15); outlet (bottom discharge) connection is always 1/2" NPT (DN15). With proper trim utilization, the unit is suitable for liquid, gaseous, or steam service.
PAGE 2
10a. Basic Regulator - (Refer to Figure 1): Regulator may be rotated around the pipe axis 360°. Recommended positions are with the spring chamber vertical upwards, or horizontal. Orient such that the spring chamber vent hole does not collect rainwater or debris. a. Recommended installation is with the spring chamber directed upwards. b. No corrosive fluid should be utilized for spring chamber loading. c.
PAGE 3
SECTION V V. SHUTDOWN 1. On systems with a bypass valve, and where system pressure is to be maintained as the regulator is shut down, slowly open the bypass valve while closing the inlet (upstream) block valve. Fully close the inlet (upstream) block valve. When on bypass, the system pressure must be constantly observed and manually regulated. Close the outlet (downstream) block valve.CAUTION CAUTION Do not walk away and leave a bypassed regulator unattended! 2.
PAGE 4
11. Clean body (1) and diaphragm flange. NOTE: On regulators originally supplied as “cleaned for oxygen service”, Option -5, -36 or -55, maintenance must include a level of cleanliness equal to Cashco cleaning standard #S-1134. Contact factory for details. C. 12. Place diaphragm gasket (6) on body (1) flange, if required. 13. Reassemble diaphragm subassembly by placing piston (3.1) in a vise (recommend using lead jaws with vise).
PAGE 5
7. Bench test unit for suitable operation. NOTE: Regulators are not tight shutoff devices. Even if pressure falls below setpoint, regulator may or may not develop bubble tight shutoff. In general, tighter shutoff can be expected with a composition seat. 8. Soap solution test around body (1) flange for leakage. Test pressure should be the maximum allowed by the range spring at the inlet. SECTION VII VII. TROUBLE SHOOTING GUIDE 1. Erratic Operation; chattering Possible Causes A.
PAGE 6
SECTION VIII VIII. ORDERING INFORMATION: NEW REPLACEMENT UNIT vs PARTS "KIT" FOR FIELD REPAIR To obtain a quotation or place an order, please retrieve the Serial Number and Product Code that was stamped on the metal name plate and attached to the unit. This information can also be found on the Bill of Material ("BOM"). a parts list that was provided when unit was originally shipped. (Serial Number typically 6 digits).
PAGE 7
Figure 1: Standard Model BQ, Metal Seat Design Figure 2: Option -5 or -36 Cryogenic, Metal Seat Design (NOTE: Mount in Horizontal line with Adjusting Screw down as shown.) Figure 4: Composition Seat Figure 3: Option -1+6 Differential, Metal Seat Design (includes Option -1 Closing Cap) IOM-BQ Item No. 1 2 3 3.1 3.2 4 5 6 7 8 9 10 11 12 13 14 15 20 21 22 23 Description Body Spring Chamber Trim (Cylinder/Piston/Seat) Piston Cylinder Diaphragm Piston Gasket Diaphragm Gasket Hex.
PAGE 8
Cashco, Inc. P.O. Box 6 Ellsworth, KS 67439-0006 PH (785) 472-4461 Fax. # (785) 472-3539 www.cashco.com email: sales@cashco.com Printed in U.S.A. IOM-BQ Cashco GmbH Handwerkerstrasse 15 15366 Hoppegarten, Germany PH +49 3342 4243135 Fax. No. +49 3342 4243136 www.cashco.com Email: germany@cashco.com Cashco do Brasil, Ltda. Al.Venus, 340 Indaiatuba - Sao Paulo, Brazil PH +55 11 99677 7177 Fax. No. www.cashco.com Email: brazil@cashco.