Series 820Direct Acting Steam PRV

SPECIFICATIONS

Diaphragm chamber

Grey iron, ductile iron or steel construction.Standard sizes: 6", 8", 10" and 15", according to required response (sensitivity).

Bonnet

Provides support to diaphragm and guides valve spring.

Spring

Heat treated and color codified to offer optimum response and broad calibration range.

Gasket Teflon gasket minimizes friction for stem smooth vertical movement and assures zero-leakage.

Bonnet supportLateral orifices allow rapid extraction from body to check sealing surfaces.

Metal disc

Stainless steels, smoothed surfaces to assure optimum seal in gases or steam.

SeatSmoothed stainless steel, high erosion resistance to ensure long operating life.

BodyIron or steel forged body for heavy duty. Flanged connection may be manufactured upon client request.

GENERAL INFORMATION

MODEL SIZE CONNECTIONS BODY MATERIAL

TRIM MATERIAL

MAX.INLET PRESSURE

MAX. TEMP

821

822

823

1" - 3 "

1" - 3 "

1" - 3 "

Threaded NPT

ANSI 150 #

ANSI 300 #

Iron ASTM A126

Steel ASTM A216 Steel ASTM A216

Steel Inox: AISI304

Steel Inox: AISI304

Steel Inox: AISI304

250

250

300

308 ℉

350 ℉

120 ℉

Main Advantages

1. Compact, durable design for higher flow requirements.2. Range of sizes after required sensitivity.3. Serviciable in line.4. Quality assurance:5. Metalography, spectometry and individual hydrostatic and leakage testing.6. Complete product traceability through test register in product data sheet.

OPERATING PRINCIPLE

Steam passes through pilot line until it reaches actuation chamber were it condenses, filling the chamber and pilot line up to siphon, thus outlet pressure (P2) is communicated to diaphragm.

Inlet pressure (P1) is regulated to outlet pressure (P2) by positioning metal disc to seat depending on required demand.

FOR CERO FLOW

When outlet pressure (P2) is at its maximum, spring compresses forcing metal disc descent until complete seal is achieved.

FOR MAXIMUN FLOW

When outlet pressure (P2) is at its minimum, force of spring is greater than force generated by diaphragm, therefore complete lift of metal disc is obtained.

MODULATING FLOW

Spring force is greater than intermediate pressure between maximum and minimum range. To minimize variation a bigger diaphragm chamber and a black spring is selected.

3

Actuation chamber

siphon

Spring force

Spring

Pilot line

Needle valve

Apparatus line

Seat

Disc

P2

P2

P1

Regulator sizing and selection must not be subject to piping size, as it depends on required capacity and differential pressure .

Cv is the accepted terminology to define the capacity of any valve. Cv is the quantity of water in GPM that passes through the valve for a 1 PSI decrease in pressure through the valve. The following Cv correspond to the standard 820 series valve sizes:

SIZING

Valve capacity increases as regulated pressure decreases. As valve reaches full flow capacity regulating in greater deviation from set point pressure (P2). Valve capacity should considered according to process flow to minimize mendored deviation.

Example: Point on the graph shows that a pressure 1(Droop) of 4.5 PSI will occur when a 1 1/2" regulator valve with a 10" chamber is working at full capacity (Cv). In the other hand, a decrease in regulated pressure (Droop) of 1.5 PSI will occur when the same valve is working at 50% capacity (point ).

CAPACITY CV

DRO

OP P

SI

1

1

2

SIZE 1" 2" 3"

Cv 10 20

With the use of the following formulas, and using the Cv value as input, valve capacity for steam can be calculated:

4

25 40 50

CRITICAL FLOW

Capacity "W" is defined as:

In these conditions flow is throttled and outlet pressure (P2) does not affect flow.

SUBCRITICAL FLOW

When outlet pressure (P2) increases, flow reduces and when outlet pressure (P2)

decreases flow increases.

Capacity "W" is defined as:

P2 ≤ ½ P1 P2 ≥ ½ P1

Body material Connections Chamber Spring

820

Iron ASTM A126

Steel ASTM A216 Steel ASTM A216

821822

821

822

823

Class Cód. Kind Cód.

NPI

ANSI 125#

ANSI 250#

ANSI 150#

ANSI 300#

11

5

4

3

2

1

2

3

4

6"

8"

10"

15"

150

100

200

250

300

Cód.Thread NPT

1"

1½

2"

2½

3"

Size Cód. Color Cód.

Green

Black

V

N

Wmax. = Cv (P + 14,7) 0.547

= Cv (P + 14,7) W MAX. = 2,1Cv 1 2 P( P + P )

Size

PRODUCT ID REFERENCE GUIDE

820 series regulator valve

Pressure gauge (P2)

Pressure gauge (P2)

steam trap

Safety relief valve

INSTALLATION

1"½ 2"½

CHAMBER AND SPRING SELECTION

1"Chamber & green

color springChamber & black

color spring

Inlet pressure

6" 8" 6" 8"Regulated Pressure (PSIG)

Min. Min. Min. Min.Max. Max. Max. Max.

20

37

34

25

25

148

145

120

97

152

29

26

23

17

34 74

70

67

63

59

28

26

23

21

17

67

64

62

58

57

12

11

9

8

7

32

30

29

28

27100

200

175

150

125

Green Spring

6" chamber

8" chamber

Black Spring

8" chamber

6" chamber

Chamber & green color spring Chamber & black color spring 1½ "

6" 8" 10" 6" 8" 10"

Regulated Pressure (PSIG)

Green Spring Black Spring

Inlet pressure

32

38

44

50

97

108

112

117

12

15

18

21

58

60

63

65

6

8

9

10

20

20

22

23

35

40

47

54

84

89

94

100

16

19

21

25

37

40

42

45

5

7

8

9

13

15

16

18

Chamber & green color spring Chamber & black color spring 2 "

6" 8" 10" 6" 8" 10"

Regulated Pressure (PSIG)Inlet pressure

56

65

72

79

86

98

120

145

149

153

20

24

27

30

34

42

46

50

54

58

10

13

15

18

21

25

27

30

33

35

35

42

50

57

59

69

76

82

89

95

17

21

24

28

30

36

40

43

47

49

15

18

22

25

28

33

36

39

43

46

8" chamber

6" chamber

10" chamber10" chamber

8" chamber

6" chamber

Cv

Cv

100

125

175

150

200

10" chamber

6" chamber

8" chamber

10" chamber

8" chamber

6" chamber

Green Spring Black Spring

5

Cv Cv

Cv Cv

125

150

100

175

6

Chamber & green color spring Chamber & black color spring2½ " 6" 8" 10"

Regulated Pressure (PSIG)Inlet pressure

CHAMBER AND SPRING SELECTION

6" 8" 10"8" 10" 15" 15"10"8"6"

min. max min. min. min. min. min. min. min.max max max max max max max

56

65

72

79

98

120

145

149

19

24

28

34

44

48

53

58

25

20

30

35

35

40

45

50

4

10

12

14

8

16

18

20

33

41

50

59

64

71

79

87

16

20

25

29

27

24

31

34

15

19

23

27

29

32

36

41

4

5

7

8

7

8

10

11

86 154 43 62 40 55 16 22 68 95 34 37 31 46 9 12

Chamber & green color spring Chamber & black color spring3 " 6" 8" 10"

Regulated Pressure (PSIG)Inlet pressure

6" 8" 10"8" 10" 15" 15"10"8"6"

min. max min. min. min. min. min. min. min.max max max max max max max

40

51

62

71

71

82

93

103

27

34

41

50

46

53

60

67

41

33

49

58

48

56

64

73

12

15

18

21

17

20

23

26

45

55

67

78

60

69

79

100

35

43

48

55

51

44

59

65

36

45

54

61

64

75

86

96

16

20

23

27

22

26

30

34

79 115 60 74 66 81 24 29 96 115 62 72 69 107 30 38

15" chamber

10" chamber

8" chamber

6" chamber

15" chamber

10" chamber

8" chamber

6" chamber

Green Spring Black Spring

Cv Cv

Cv Cv

Green Spring Black Spring

100

125

150

175

200

100

125

150

175

200

100

125

150

175

200

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