02 BOPs / M02-040 - Liquid Process Piping - Part 5 - Valves - US

Liquid Process Piping - Part 5: Valves – M02-040

Figure 10-5. Critical Pressure Ratio

(Source: Fisher, Control Valve Handbook, 2nd Ed., p. 67)

10-19

Liquid Process Piping - Part 5: Valves – M02-040

C

v

'

Q

s.g.

N1

)P

21.5 m 3/hour

C

v

'

1.0

'11.4

0.085

496 kPa

N

F Q

R

2

C2

1/4

Re '

4

d

m

v

% 1

v

< Rm1/2CV1/2

N2

d4

1/4

(76,000)(0.7)(21.5)

(0.7)2(11.4)2

Re '

%1

v

(1.13)(0.7)1/2(11.4)1/2

(0.00214)(100)4

Rev ' 3.57 x 105

FR = 1.0 from Figure 10-4 (a viscosity correction is not required due to the high Reynolds number).Therefore, Cvc = 11.4.

Step 5. From manufacturer's data, a 25 mm, 60 V-port ball valve at full open in a 50 mm pipe has a Cv of 11.2 and a Rm of 0.75. Therefore, neck the connecting piping down to 50 mm, and select a 25 mm V-port ball valve (has an equal percentage flow characteristic).

Step 6. The allowable pressure drop of the system is compared to the actual valve differential pressure to confirm that the valve will operate satisfactorily.

1/2

rc ' 0.96 & 0.28 Pv

Pc

' 0.96 & 0.28	1.85kPa 1/2

22,090kPa rc ' 0.96

)Pallow ' Rm2 (Pi & rc Pv)

' (0.75)2[1030 kPa & (0.96)(1.85 kPa)]

)Pallow ' 578 kPa at max. flow (full open)

Pallow P at maximum flow, therefore, the valve is acceptable.

10-4. Valve Schedule

Manymanufacturers have PC-based sizing programs that will size and select their optimum valve for a specific application. In addition, computerized piping system design programs mayalso have valve sizing and selection routines that will select the optimum valve in their databases. Although these sizing programs can provide useful data, the optimum valve for a particular application may be found elsewhere. For design purposes, contract drawings include a valve schedule to aid in the bidding and proper supply of valves.

a. Valve Schedule

Table 10-10 presents a valve schedule that is included in the contract drawings for liquid process piping design.

b. Valve Operators Schedule

Table 10-11 is a valve operator schedule that is sometimes included in the contract drawings. This schedule is used when additional information, beyond that shown on a valve schedule, is required.

10-20

Table 10-10

Valve Schedule

Valve

Size

Flange

Screwed

Design

Body

Trim

Bolting

Tag/Ref

Description

Range

Rating

Ends

Rating

Materials

Materials

Materials

Operation

Service

Remarks

V120

Ball Valve, Full Port

50 mm &

- -

Taper

1.39 MPa

316 SS

316 SS Ball & Stem

- -

Lever

IWW, SLG,

Positive Shut-off

Smaller

ANSI B2.1

Glass Filled TFE

WPS

Seats, TFE Seals

V121

Ball Valve, Full Port

80 mm

ANSI B16.5

- -

689 kPa

316 SS

316 SS Ball & Stem

CS

Lever

SW, ALT,

Instrument Isolation

Positive Shut-off

Class 150

Glass Filled TFE

ASTMA 307

RO, AL,

Valves Only

Seats, TFE Seals

Gr B

SWW, RL

V122

Ball Valve, Full Port

40 mm &

ANSI B16.5

- -

1.03 MPa

316 SS

316 SS Ball & Stem

CS

Lever

WCR

Positive Shut-off

Smaller

Class 300

Glass Filled TFE

ASTMA 307

Seats, TFE Seals

Gr B

V123

Solid Wedge Gate Valve

50 mm &

ANSI B16.5

- -

1.03 MPa

CS

13% Cr Steel Seats &

CS

Handwheel

SLP

O.S. & Y., Rising Stem

Larger

Class 300

ASTMA 216

SS Stem

ASTMA 307

GR WCB

Gr B

V124

Double Disc Gate Valve

50 mm &

ANSI B16.5

- -

689 kPa

CS

UT Trim

CS

Handwheel

SL

O.S. & Y., Rising Stem

Larger

Class 150

ASTMA 216

316 SS Stem

ASTMA 307

GR WCB

Gr B

V150

Swing Check Valve

50 mm to

ANSI B16.5

- -

689 kPa

CS

13% Cr Steel Seats &

CS

- -

XLT, ALT,

All Drain Points to be

300 mm

Class 150

ASTMA 216

Disc

ASTMA 307

RL, AL,

Threaded & Plugged

GR WCB

Gr B

SLO, PLO

V151

Swing Check Valve

50 mm &

- -

Taper

1.39 MPa

Bronze

Bronze

- -

- -

PW

All Drain Points to be

Smaller

ANSI B2.1

Threaded & Plugged

V152

Y-Pattern Check Valve

50 mm &

- -

Socket

17.2 MPa

CS

13% Cr Steel Seats &

- -

- -

FWH

Smaller

Weld

ASTMA 105

302 SS Spring

V153

Lined Wafer Check Valve

250 mm

Fit

- -

689 kPa

PFA Coated

PFA Coated Steel

- -

- -

DWH

Between

CS

Class 150

V154

Wafer Style Check Valve

100 mm

Fit

- -

689 kPa

410 SS

302 SS

- -

- -

AP

All Drain Points to be

to

Between

ASTMA 276

Threaded & Plugged

250 mm

Class 150

PCV-452

Globe Valve, Bolted

100 mm

ANSI B16.5

- -

689 kPa

CS

SS

CS

Pneumatic

RCY

Bonnet,

Class 150

ASTMA 216

ASTMA 307

Diaphragm

O.S. & Y., Rising Stem

GR WCB

Gr B

R.A.

FCV-501

Butterfly Valve

100 mm

Fit

- -

689 kPa

PFA Lined

PFA Lined D.I. & SS

- -

Electric

AG, AV

Between

D.I.

Stem

Class 150

FCV-625

Butterfly Valve

300 mm

Fit

- -

689 kPa

PFTE Lined

PTFE Lined CS &

- -

Electric,

DWH

Between

CS

SS Stem

Enclosed

Class 150

Gear

Source: Example Schedule by SAIC, 1998.

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040-M02 – Valves 5: Part - Piping Process Liquid

Table 10-11

Valve Operator Schedule

Operator

Maximum

Electrical

Materials of

Failure

Enclosure

Associated

Tag/Ref

Description

Type

Air Pressure

Supply

Action

Construction

Mode

Rating

Accessories

Valve

Remarks

V120

Ball Valve, Full Port

Pneumatic,

103 kPa

- -

R.A

Manufacturer’ s

F.O.

Weather

Positioner,

PCV-452

Positive Shut-off

Diaphragm

Standard with Epoxy

Proof

Filter/Regulator,

Coating

Handwheel

V121

Ball Valve, Full Port

Pneumatic,

1.03 MPa

- -

D.A.

Manufacturer’ s

F.C.

Weather

Positioner,

PCV-1013

Positive Shut-off

Piston

Standard with Epoxy

Proof

Filter,

Coating

Handwheel

V122

Ball Valve, Full Port

Pneumatic,

1.03 MPa

- -

D.A.

Aluminum

F.L.

NEMA 4

I/P, Filter

FCV-485

Positive Shut-off

Rotary

V123

Solid Wedge Gate Valve

Electric,

- -

120 V,

D.A.

Manufacturer’ s

F.L.

NEMA 4

FCV-501

O.S. & Y., Rising Stem

Rotary

20 A,

Standard with Epoxy

1 ph

Coating

V124

Double Disc Gate Valve

Electric,

- -

120 V,

D.A.

Manufacturer’ s

F.C.

NEMA 4X

Enclosed Gear,

FCV-625

O.S. & Y., Rising Stem

Rotary

20 A,

Standard

1 ph

Source: Example Schedule by SAIC, 1998.

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040-M02 – Valves 5: Part - Piping Process Liquid