Emerson 75A Data Sheet

Type 75A Water Pressure Regulator

Bulletin 71.1:75A

August 2009

W2248

EXTERIOR

Figure 1. Type 75A Regulator

Introduction

The Type 75A regulator is designed to reduce
domestic or industrial water pressure, thus protecting

plumbing xtures and meters from high-pressure
surges. The Type 75A is self-contained, requiring no
external control line for operation.

Downstream pressure is directly registered under
the diaphragm. As the downstream pressure

increases, the diaphragm force overcomes the spring

W0057

SECTIONAL VIEW

FOR NPS 1/2, 3/4, 1, AND 1-1/2

(DN 15, 20, 25, AND 40) BODIES

compression, causes the valve disk to rise, and
reduces ow through the regulator.

If the downstream pressure decreases, the spring force
pushes the valve yoke and disk down to open the body
port. This permits increased ow and increases outlet
pressure to the desired level. The spring for each
regulator allows operation over an outlet pressure range
of 20 to 80 psig (1,4 to 5,5 bar). The outlet pressure

setting is easily changed by turning the adjusting screw.

D100116X012

www.emersonprocess.com/regulators

Bulletin 71.1:75A

Specications

Body Size

NPS 1/2, 3/4, 1, and 1-1/2 (DN 15, 20, 25, and 40)
with integral cast seats

NPS 2 and 2-1/2 (DN 50 and 65) with
threaded-in seats

Maximum Inlet Pressure

(1)

200 psig (13,8 bar)

Outlet Pressure Ranges

20 to 80 psig (1,4 to 5,5 bar)

Maximum Allowable Outlet Pressure

(1)

10% above spring setting, or 5 psig (0,34 bar)

Minimum Operating Differential

5 psi (0,34 bar)

Maximum Operating Temperature

-20° to 150°F (-29° to 66°C)

Construction Materials

Body: Bronze
Spring Case: Cast iron
Threaded-in Orice (NPS 2 and 2-1/2
(DN 50 and 65) units only): Bronze
Valve Disk and Holder: Nitrile (NBR) and bronze
Diaphragm: Nitrile (NBR)

(1)

(1)

above setting, whichever is greater

1. The pressure/temperature limits in this bulletin or any applicable standard limitation should not be exceeded.

Table 1. Capacity Chart for Type 75A Regulator

CAPACITIES IN GPM (l/min) OF WATER

BODY SIZE, NPS (DN)

5 (0,34) 7 (0,48)

1/2 (15)
3/4 (20)

1 (25)

1-1/2 (40)

2 (50)

2-1/2 (65)

1. The 7 psig (0,48 bar) offset pressure and the related capacities are considered the upper limits of ows consistent with good piping practices and maximum uid velocities of
10 feet per second (3,05 m/s).

8 (30,3)

16 (60,6)

25 (94,6)

50 (189)

75 (284)

115 (435)

10 (37,9)
20 (75,7)

33 (125)
65 (246)

95 (360)

140 (530)

Droop, PSIG (bar)

(1)

10 (0,69) 15 (1,0)

14 (53,0)

28 (106)

45 (170)
85 (322)

125 (473)
185 (700)

19 (71,9)

40 (151)

60 (227)

115 (435)

175 (662)
260 (984)

WIDE-OPEN CV FOR

RELIEF SIZING

4.3

8.4

13.5

28.0

39.0

64.0

2

Bulletin 71.1:75A

(+ 0,34)

+ 5

(0)

0

(- 0,34)

- 5

(-0,48)

- 7

(-0,69)

- 10

TO 320

(-1,0)

- 15

OFFSET, PSIG (bar)

(-1,4)

- 20

0 20 40 60 80 100 120 140 160 180 200 220 240 260
(0) (75,7) (151) (227) (303) (379) (454) (530) (606) (681) (757) (833) (908) (984)

NPS 1/2

(DN 15)

NPS 3/4

(DN 20)

NPS 1

(DN 25)

NPS 1-1/2

(DN 40)

NPS 2

(DN 50)

AT -20

NPS 2-1/2

(DN 65)

WATER FLOW, GPM (l/m)

Figure 2. Type 75A Sizing Curves

Overpressure Protection

As is the case with most regulators, Type 75A has

maximum inlet pressure ratings which exceed the
outlet pressure ratings. Overpressuring any regulating
equipment may be hazardous. If actual inlet pressure
can exceed the outlet pressure ratings, some type of
overpressure protection is needed.

Sizing Information

Flow capacity and the maximum permissible offset

pressure that the system can tolerate determine the

correct regulator size for your application. Consult the
Type 75A Sizing Curves (Figure 2) and the Capacity
Chart (Table 1) to size the regulator. Several choices
may provide the required ow rate.

For example, if desired water ow is 30 GPM
(114 l/m), the rst intersecting curve (Figure 2) is
that of the NPS 3/4 (DN 20) regulator. At that point,
offset is 11 psi (0,76 bar), which is outside the limits of
good piping practice. Moving upward again, the next
intersecting curve is that of the NPS 1 (DN 25) regulator.
Here, offset is 6 psi (0,41 bar). This rating is permissible
and the NPS 1 (DN 25) regulator is acceptable.

Ordering Information

In order to prevent delays in order processing, please
specify type numbers and regulator size clearly.

3

Bulletin 71.1:75A

B

A

Figure 3. Dimensions

BODY SIZE,

NPS (DN)

1/2 (15)
3/4 (20)

1 (25)

1-1/2 (40)

2 (50)

2-1/2 (65)

E

D

C

A B C D E

9.75 (248)

11.25 (286)

12.25 (311)

13.62 (346)

18.62 (473)

19.12 (486)

DIMENSIONS, INCHES (mm)

7.12 (181)

8.38 (213)

9.12 (232)

9.88 (251)

13.88 (353)

14.12 (359)

4.31 (109)

5.44 (138)

6.62 (168)

8.19 (208)

9.38 (238)

9.38 (238)

3.75 (95)

4.25 (108)

4.75 (121)

5.88 (149)

6.38 (162)

7.75 (197)

1.88 (48)

2.12 (54)

2.38 (60)

2.94 (75)

3.19 (81)

3.88 (99)

Industrial Regulators

Emerson Process Management
Regulator Technologies, Inc.

USA - Headquarters
McKinney, Texas 75069-1872 USA
Tel: [phone]
Outside U.S. 1-972-548-3574

Asia-Pacic
Shanghai, China 201206
Tel: [phone]

Europe

Bologna, Italy 40013
Tel: [phone]

Middle East and Africa

Dubai, United Arab Emirates

Natural Gas Technologies

Emerson Process Management
Regulator Technologies, Inc.

USA - Headquarters
McKinney, Texas 75069-1872 USA
Tel: [phone]
Outside U.S. 1-972-548-3574

Asia-Pacic
Singapore, Singapore 128461
Tel: [phone]

Europe

Bologna, Italy 40013
Tel: [phone]
Gallardon, France 28320
Tel: [phone]

TESCOM

Emerson Process Management
Tescom Corporation

USA - Headquarters
Elk River, Minnesota 55330-2445 USA
Tel: [phone]

Europe

Selmsdorf, Germany 23923
Tel: [phone]

Tel: [phone]

For further information visit www.emersonprocess.com/regulators

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