GE mn-28000_series Service Manual download pdf (Page 5)

Masoneilan VariPak Adjustable Cv Control Valves Instruction Manual | 5

2. Operation

The Masoneilan VariPak microﬂow control valve

features a very wide range of rated ﬂow coefﬁcients

), from 0.004 to 3.8.

Two types of actuators are available:

- The VariPak 28001 with a single lever, designed for

just one rated C

. This version is used when enough is

known about the operating conditions when sizing the

valve.

- The VariPak 28002 with an adjustable rated C

. This

valve uses a patented lever system to adjust the rated

on site to suit the actual operating conditions,

thereby avoiding any oversizing in ﬂow capacity.

Each plug and seat ring combination can be adjusted

without changing the control signal.

2.1 PRECISE ADJUSTMENT OF THE VARIPAK 28002

ADJUSTABLE-C

VALVE

The valve is adjusted using a simple, but robust,

crossed-lever system with an adjustable fulcrum. This

can be done easily by hand, either before installation or

during operation. For example, an application requiring

a theoretical C

of 0.006 could be handled using a

VariPak 28002 with a maximum C

of 0.010, that can

subsequently be calibrated on site between 0.004 and

0.010.

2.2 FLOW COEFFICIENT OF VARIPAK 28001

SINGLE-LEVER AND 28002 ADJUSTABLE-C

VALVES

2.2.1 Plug/seat ring combinations (trim)

Eight plugs and ﬁve seat rings are used to

make up the ten available plug and seat ring

combinations, identiﬁed by codes from 0 to 9

(see ﬁgure 2). The shape of each plug and the

port diameter of the seat ring can be used to

match parts with the table in ﬁgure 2.

The difference between the four plugs in trim

Nos. 6 to 9 lies in the angle of the ﬂat machined

on the tip. The same seat ring (3e) and the

same spacer (3f) are used in all four cases (see

ﬁgure 2).

Use the table in ﬁgure 1 to select the plug and

seat ring combination to obtain the C

value or

range of C

values you require.

Trim No.

FLOW COEFFICIENT C

VARIPAK

28001

VARIPAK 28002

MIN. RISK FREE MAX.

0.0040 0.0016 0.0020 0.0024 0.0028 0.0032 0.0036 0.0040

0.010 0.004 0.005 0.006 0.007 0.008 0.009 0.010

0.025 0.010 0.013 0.016 0.019 0.021 0.023 0.025

0.050 0.020 0.025 0.030 0.035 0.040 0.045 0.050

0.10 0.04 0.05 0.06 0.07 0.08 0.09 0.10

0.25 0.10 0.13 0.16 0.19 0.21 0.23 0.25

0.6 0.25 0.30 0.35 0.4 0.45 0.5 0.55 0.6

1.2 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2

2.3 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3

3.8 1.5 1.9 2.3 2.6 2.9 3.2 3.5 3.8

Figure 1

1 2 3 4 5 6 7 8 9 10 ... 24 25

Comments to this Manuals

No comments

GE mn-28000_series Service Manual Page 5

Comments to this Manuals

Related products and manuals for Motor vehicle accessories & components GE mn-28000_series