background image

Refrigerating Specialties Division

1

BULLETIN DN23-06

B

A4A Series

January 2007

Installation, and Service Information

ADAPTOMODE

®

 INLET

PRESSURE REGULATORS

Types: A4AS-DN, A4AB-DN,

A4AD-DN, A4AZ-DN

PORT SIZE 20 - 100 mm (3/4" - 4")
FOR AMMONIA, R-12, R-22, R-502
OTHER REFRIGERANTS AND OIL

FEATURES

• Pilot operated characterized Modulating Plug for precise

control

• Suitable for all common refrigerants and oil
• 2

8

 bar (

406

 psig) design pressure (PS)

• Flanges for threaded or welded steel pipe and copper

tube (copper not for ammonia)

• Unique Modular construction
• Interchangeable parts
• Easy to service
• Close coupled strainers, optional
• Stainless Steel Diaphragm
• Stainless Steel Pilot Seat
• Manual Opening Stem
• Complies with Pressure Equipment Directive 97/23/EC

Description:

These compact, heavy duty, pilot operated, Inlet Pressure Regulators
are suitable for Ammonia, R-12, R-22, R-502 and other common
refrigerants and fluids approved for use in refrigeration systems.

All A4 Regulators are pilot operated using upstream pressure for the
opening force and require a minimum 0.14 bar (2 psi) pressure drop
to fully open.

These valves are generally ordered with close coupled upstream
strainer to prevent entrance of foreign material into the valve and the
rest of the system. (See current Bul. DN00-10 for strainer information.)

Purpose

Modulates flow of refrigerant gas or liquid to maintain a constant
upstream (or inlet) pressure as set-for, despite load fluctuations.

The fluid temperature range for the A4 Series of Regulators is -45°C
to 105°C (-50°F to 220°F).

Principles of Operation (See Fig. 1)

The inlet pressure enters the space under the diaphragm through
passage N. When the force created by the pressure exceeds the force
of the range spring, the diaphragm is lifted off the pilot seat allowing
pressure to enter on top of the power piston. This causes the power
piston to move downward forcing the modulating plug to open and
modulate to maintain constant inlet pressure. An increase in inlet
pressure lifts the diaphragm further, allowing more pressure on top of
the power piston and opening the valve wider. A decrease in inlet
pressure causes the diaphragm to move closer to the pilot seat
reducing the pressure on the top of the power piston and causing the
closing spring to reduce the valve opening. The pressure on top of the
power piston is controlled by the flow through the pilot seat and the
bleed off through the bleed hole in the power piston and through the
clearance between the piston and cylinder. A minimum of 0.14 bar (2
psi) pressure drop across the valve is required to open it fully.

The A4A Inlet Pressure Regulator therefore opens on a rise in the
inlet pressure above its set point and closes on a drop in inlet pressure
below its set point. The inlet pressure set point is not appreciably
affected by variations in the outlet pressure.

Manual Opening Stem

All Type A4A Regulators are provided with a manual opening stem. To
open the regulator manually, back the stem out (turn counter-clockwise)
until it stops. To put the regulator into automatic operation, turn the
stem in (clockwise) until only the flats on the stem protrude from the
packing nut.

I S O   9 0 0 1   C E R T I F I E D

A4AZ

Fig. 1

A4AS-DN

    A4AD-DN

A4AZ-DN

     A4AB-DN

310214

Содержание ADAPTOMODE A4AB-DN

Страница 1: ...C 50 F to 220 F Principles of Operation See Fig 1 The inlet pressure enters the space under the diaphragm through passage N When the force created by the pressure exceeds the force of the range spring...

Страница 2: ...g the regulator function i e not regulating However in the wide open mode the regulator will still require the 0 14 bar 2 psi minimum pressure drop When the solenoid is de energized the valve function...

Страница 3: ...Refrigerating Specialties Division 3 BASIC ADAPTOMODE FUNCTIONS Fig 2 A4AZ Fig 3 A4AS Fig 4 A4AB Fig 5 A4AD...

Страница 4: ...A Regulators General Procedure The construction of the regulator and the method of disassembly are relatively simple but some procedures must be followed to avoid damage The following describes the pr...

Страница 5: ...Port Pipe Plug 28 Adapter Body 29 Gasket Body 30 Piston Stem 31 Screw Body 32 Body 33 Throttling Plug Asm 34 Spring Closing 35 Dirt Wiper Retainer 36 Dirt Wiper 37 Seal Bottom Cap 38 Bottom Cap 39 Sc...

Страница 6: ...dular Solenoid Pilot Figs 10 and 12 This solenoid pilot may be mounted on either Pad 1 or 2 depending on the function desired see pages 2 and 3 Before working on any Fig 11 A2D2 A2D MODULAR PRESSURE P...

Страница 7: ...440 60 Yellow Red leads 0 39 0 13 1 115 50 Yellow Blue leads 1 22 0 21 1 230 50 Yellow leads 0 65 0 26 1 Other Contact Factory On transformer coil the 6 volt leads are always black Fig 12 S6A MODULAR...

Страница 8: ...t Range D make sure has 2 open ruptured or badly deformed diaphragms Diaphragm follower stuck damaged or frozen Clean or replace Install follower carefully A4AS A4AB Modular Solenoid Pressure drop acr...

Страница 9: ...lange Pipe Size Socket I D Neck O D Number 2 Pkg O D I D Flge Pkg Pipe Size Pkg No Socket Weld No 2 Pkg mm Inches Inches 2 Pkg Inches NW No Inches mm Inches mm Weld Neck Inches mm Inches mm 20 3 4 3 4...

Страница 10: ...40 3 42 4 1 61 L ADAPTER 2 A4A DN DUCTILE IRON GGG 40 3 COVER BOTTOM A4A S4A 1 5 8 to 2 1 2 DUCTILE IRON GGG 40 3 BONNET A4W DUCTILE IRON GGG 40 3 COMPONENT DESCRIPTION MATERIAL Kv VOLUME BODY 2 1 2...

Отзывы: