LowFlow JBDL User Manual

I & M JBDL Series

3170 Wasson Road • Cincinnati, OH 45209 USA

Phone [phone] • Fax [phone]

lowfl[email protected] • www.lowflowvalve.com

Warning: Low Flow Regulators must only be used, installed and repaired in accordance with these Installation &
Maintenance Instructions. Observe all applicable public and company codes and regulations. In the event of leak­age or other malfunction, call a qualified service person; continued operation may cause system failure or a general
hazard. Before servicing any valve, disconnect, shut off, or bypass all pressurized fluid. Before disassembling a valve,
be sure to release all spring tension.

Please read these instructions carefully!

Your LowFlow/Jordan product will provide you with long,
trouble-free service if it is correctly installed and main­tained. Spending a few minutes now reading these in­structions can save hours of trouble and downtime later.
When making repairs, use only genuine LowFlow Valve
parts, available for immediate shipment from the factory.

Ideal Installation

Outlet
P2

Supply
P1

JBDL

Bypass

Installation & Maintenance Instructions for

JBDL Series Back Pressure Regulators

mately ten pipe diameters upstream, and within
sight. If you have ordered your JBDL with inlet
gauge option on the valve body, please note that
the pressure as registered on the gauge may be
slightly different than a gauge located downstream.

4. All installations should include an upstream relief
device if the inlet pressure could exceed the pres­sure rating of any downstream equipment or the
maximum inlet pressure rating of the unit.

5. Flow Direction: install so that the flow direction
matches the inlet/outlet marking on the main regula­tor body (1).

6. For best performance, install in well drained horizon­tal pipe.

7. Basic regulator - regulator may be rotated around
the pipe axis 360°. Recommended position is with
knob assembly (3) vertical upwards.

8. Regulators are not to be buried underground.

9. For insulated piping systems, recommendation is to
not insulate regulator.

To Drain To Drain

Figure 1.

Preferred Installation

Refer to Figure 1.

Caution! Installation of adequate overpressure pro­tection is recommended to protect the regulator from
overpressure and all downstream equipment 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. An inlet pressure gauge should be located approxi-

Principles of Operation

1. Movement occurs as pressure variations register on
the diaphragm (8). The registering pressure is the
inlet, P1, or upstream pressure. The range spring (4)
opposed diaphragm (8) movement. As inlet pres­sure rises, the diaphragm (8) pushes up against the
range spring (4) opening the port. As inlet pressure
decreases, the range spring (4) pushes down and
closes the port.

2. A complete diaphragm (8) failure will cause the
regulator to fail closed.

Start Up

Caution! Do not exceed the maximum rated pressure
of the regulator if installed for a hydrostatic test. Iso­late the unit if the test is above the valve rating.

1. Start with the block valves closed. A bypass valve

should be used to maintain upstream pressure in the
system without changing the following steps.

2. Relax the range spring (4) by turning the adjusting

knob (3) counter-clockwise (CCW) until there is no
noticeable spring tension.

3. Slowly open the inlet block valve. Note: if no bypass
valve is installed, extra caution should be used in
starting up a cold system; i.e. do everything slowly.

4. Slowly open the outlet (downstream) block valve.

5. Slowly rotate the regulator adjusting knob (3) clock­wise (CW) until flow begins.

6. Develop system flow to a level near its expected nor­mal rate, and reset the regulator set point by turning
the adjusting knob (3) CW to increase inlet pressure,
or CCW to reduce inlet pressure.

7. Reduce system flow to a minimum level and observe
set point. Inlet pressure will rise from the set point of
Step 6.

Shutdown

1. On systems with a bypass valve, and where sys-

tem pressure is to be maintained as the regulator
is shutdown, slowly open the bypass valve while
closing the inlet (upstream) block valve. (When on
bypass, the system pressure must be constantly
observed and manually regulated.) CAUTION! Do

not walk away and leave a bypassed regulator
unattended.

2. If the regulator and system are to both be shut

down, slowly close the inlet (upstream) block valve.
Close the outlet (downstream) valve only if regulator
removal is required.

spring housing (2).

2. If valve is removed from the line, clamp the valve
body in a vise upside down. Remove the bottom cap
(9), seat holder (11), and seat (10). Discard the seat
(10). Place body right-side up and clamp in vise again.

3. Remove spring housing (2), spring guide (5), and
range spring (4).

4. Remove diaphragm assembly parts (6), (8), (7), (12),
and (13). See Figure 2.

5. Unscrew the lower diaphragm plate (7) from the up­per diaphragm plate (6). Discard the old diaphragm
(8) and replace with new one. Remove and replace
the backup ring (16) and o-ring (15) off of the plug.
Inspect remaining parts of the diaphragm assembly
and replace if necessary and reassemble. Note: Use
only parts manufactured and supplied by LowFlow
Valve for these parts.

6. Place diaphragm assembly (6), (8), (7), (12), and (13)
back into the body cavity (1).

7. Replace range spring (4) and spring guide (5) on top
of the upper diaphragm plate (6). Replace the spring
housing (2) and knob assembly (3).

8. Reorient the valve so it is upside down again.

9. Place the new soft seat (10) into the seat holder (11)
and put back into the bottom of the body (1).

10. Remove the o-ring (14) from the bottom cap and
install the replacement.

11. Install the bottom cap (9) back into the body cavity (1).

Maintenance

Standard Repair Kit Parts are identified on the parts
listing by an ** after the item number. LowFLow Valve
recommends that all of these parts be replaced during
servicing.

Warning! System Under Pressure. Prior to perform­ing any maintenance, isolate the regulator from the
system and relieve all pressure. Failure to do so could
result in personal injury.

A. General

1. Maintenance procedures can be done after re­moval of the regulator unit from the pipeline where
installed; it may be maintained in-line if it is safe to
do so.

2. Always follow local or company procedures for
removal, handling, cleaning, and disposal of non­reuseable parts, i.e. gaskets, etc.

B. Trim Replacement

1. Remove adjusting knob (3) completely from the

Figure 2. Diaphragm Subassembly

-2-

Troubleshooting

If You Experience Erratic Control:

• Regulator may be oversized. Oversizing causes

cycling and hunting, and reduces the rangeability
of the valve - make certain that your valve has been
correctly sized according to your application condi­tions.

• Valve seat (10) may be defective - replace seat

holder (11) and soft seat (10).

• Valve plug (12) may not be moving freely - inspect

the diaphragm assembly.

• Weakened/broken return spring (13) - Determine

if corrosion is causing plug (12) to not move freely.
Replace return spring (13).

If You Experience Upstream Pressure Build-up or In­ability to Maintain Regulated Pressure:

• Inspect for jamming between upper diaphragm plate

(6) and spring housing (2).

• Diaphragm (8) may have failed - replace as neces-

sary.

• Piping may be blocked or undersized.

• Range Spring (4) may be set too high or may be bro-

ken - inspect and reset or replace as necessary.

• The valve may be undersized for required flow -

make certain that the valve has been sized correctly.

If the Regulator can’t pass sufficient flow:

A. Downstream blockage

1. Check system; isolate (block flow at regulator

inlet, not outlet).

2. Relocate regulator if necessary

B. No pressure relief protection

1. Install safety relief valve, or rupture disc.

C. Restricted diaphragm movement

1. Ensure there are no obstructions in the vent
hole of the spring housing (2), and check for
icing on the spring.

-3-

Cross Section View

Item

Description Quantity

No.

1 Body 1
2 Housing 1
3 Knob Assembly 1
4 Spring 1
5 Spring Guide 1
6 Upper Diaphragm Plate 1
7 Lower Diaphragm Plate 1
8 Diaphragm 1
9 Bottom Cap 1

10 Seat 1

11 Seat Holder 1
12 Plug 1
13 Return Spring 1
14 O-Ring 1
15 O-Ring 1
16 Back-Up Ring 1
17 Shcs 6
18 Lock Washer 6

Bulletin IM-JBDL-0414

3170 Wasson Road • Cincinnati, OH 45209 USA

Phone [phone] • Fax [phone]

lowfl[email protected] • www.lowflowvalve.com