Van Air Systems PLD 8-2.8 User Manual

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Page 1

INSTALLATION, OPERATION AND

MAINTENANCE INSTRUCTIONS

PIPE LINE DEHYDRATOR FOR NATURAL GAS

PLD 8-2.8 thru PLD 36-2.8

PN 32-0280

REV A

FEBRUARY 2011



WARNING

DO NOT REMOVE, REPAIR OR REPLACE ANY ITEM ON THIS VESSEL WHILE IT IS UNDER PRESSURE.

DO NOT OPERATE IF THERE IS A LEAK IN VESSEL. IMMEDIATELY TAKE VESSEL OUT OF SERVICE AND CALL YOUR CERTIFYING AUTHORITY. IF THERE IS A LEAK, DEPRESSURIZE

VESSEL, INSPECT, REPAIR AND OR REPLACE AS NECESSARY.

DO NOT OPERATE ABOVE MAXIMUM WORKING PRESSURE (MWP) AND OR ABOVE MAXIMUM OPERATING TEMPERATURE (DEGREES OF).

DO NOT WELD OR GRIND VESSEL. IT WILL NOT BE SAFE TO OPERATE.

DO NOT OPERATE IF THE VESSEL HAS BEEN DAMAGED BY FIRE. TAKE OUT OF SERVICE IMMEDIATELY AND NOTIFY YOUR CERTIFYING AUTHORITY.

ANY DAMAGE TO VESSEL CAN MAKE IT UNSAFE. INSPECT OUTSIDE AND INSIDE OF VESSEL REGULARLY FOR CORROSION OR ANY DAMAGE (I.E., DENTS, GOUGES OR BULGES). IF DAMAGED, TAKE OUT OF SERVICE IMMEDIATELY. CALL YOUR CERTIFYING AUTHORITY.

Page 2

1.0 OPERATION

A Pipeline Dehydrator removes the water vapor (humidity) present in the gas stream. The process cleans and dries the gas as it

ows through a vessel which is lled with a special drying agent

(desiccant). The dehydrator operates automatically. There are no

moving parts and no external source of power is required.

"Wet" natural gas enters the lower portion of the dryer where liquid

water and solid particles are separated by gravity and fall to the bottom of the vessel. The gas moves upward through the prebed and drying bed of Van Gas desiccant tablets. The tablets attract

and absorb moisture from the gas as it ows through the desiccant

bed. The tablets dissolve gradually as they absorb the moisture

and the liquid falls to the bottom of the vessel. The liquid run off in

the prebed creates an extended surface area capable of removing additional moisture from the gas. This conserves the absorbent

desiccant tablets. The "dry" natural gas ows through the dryer

outlet.

The solution of dissolved desiccant and water that falls into the claim area at the bottom of the vessel must be drained regularly to

prevent the vessel from ooding. An automatic drain valve can be installed to prevent the vessel from ooding.

2.0 INSTALLATION

2.1 LOCATION

The ability of a dehydrator to dry natural gas is dependent on the correct location of the unit. Temperature and pressure are the keys to selecting the proper location.

IMPORTANT

ALWAYS PROCESS THE GAS THROUGH THE DEHYDRATOR AT THE LOWEST TEMPERATURE AND THE HIGHEST PRESSURE.

INLET GAS TEMPERATURE: Lower inlet gas temperatures will

result in a lower moisture content at the outlet of the dehydrator. Locate the dehydrator at the point where temperature is the lowest.

CAUTION

The gas temperature should not exceed:

100°F for GASDRY PRIME

80°F for GASDRY PEAK 100°F for GASDRY MAX

MAXIMUM CAPACITIES - MSCFD

1,000 STANDARD CUBIC FEET PER DAY

AFTERCOOLING: If the gas being processed has been compressed

mechanically, an aftercooler, nned tubing or extended run of piping

will usually be necessary to reduce the inlet gas temperature to the dehydrator.

OPERATING PRESSURE: More gas can be processed through the dehydrator at higher pressures. Locate the dehydrator at the highest practical pressure, but do not exceed the maximum rated working pressure of the dehydrator. Refer to the capacity chart located below.

CAPACITY: The chart below indicates the maximum ow rate

through the dehydrator for a 24 HOUR period. To calculate the capacity for a rate per minute just multiply the MSCFD RATE (from chart ) by 0.6944 example:

A PLD 12-2.8 operating at 50 PSIG has a maximum MSCFD rate of

79. To gure the SCFM multiply 79 MSCFD x 0.6944 which equals

54.86SCFM

NOTE: This is the MAX instantanious ow that can be processed through the dehydrator without deterioration of the drying

performance.

MODEL

NO.

PLD 8-2.8

PLD 12-2.8

PLD 16-2.8

PLD 20-2.8

PLD 24-2.8

PLD 30-2.8

PLD 36-2.8

PAGE 2

PART

NO.

80-1397

80-1399

80-1401

80-1403

80-1405

80-1468

80-1407

MAXIMUM WORKING

PRESSURE

280 PSIG

50 PSIG

125

192

280

447

672

100 PSIG

141

221

341

497

793

1191

150 PSIG

108

202

317

489

714

1139

1711

175 PSIG

124

233

365

563

822

1312

1970

200 PSIG

141

263

413

638

930

1485

2230

225 PSIG

157

294

462

712

1038

1658

2490

250 PSIG

173

325

510

786

1147

1831

2749

280 PSIG

193

362

567

875

1277

2038

3061

Page 3

2.2 PIPING AND ANCILLARY EQUIPMENT

2.3 INLET AND OUTLET PIPING

IMPORTANT

COMPLY WITH ALL FEDERAL, STATE, AND LOCAL REGULATIONS CONCERNING INSTALLATION OF NATURAL GAS SYSTEMS.

COMPLIANCE TO AND KNOWLEDGE OF ALL REGULATIONS IS THE RESPONSIBILITY OF

THE INSTALLER.

Make sure that the temperature of gas is not over the maximum for the desiccant being used. If gas temperature is too high, cool it prior to the dehydrator.

Mount the dehydrator on a level surface capable of supporting the weight of the vessel, such as a cement pad or a skid.

Install a pressure relief valve in the up-stream piping (relief valve not furnished). A relief valve must be installed to

conform with the ASME Boiler and Presssure Vessel Codes,

Section VIII, Division 1 UG-125, Paragraph (1) and OSHA

standards. Also comply with all applicable Federal, State,

and Local codes.

FIGURE 2-A RECOMMENDED INSTALLATION

Two shut-off valves should be installed (not furnished with dehydrator)-one at dryer inlet and another at dryer outlet. See Figure 2-A Recommended Installation.

Connect the inlet and outlet piping as shown in Figure 2-A.

NOTE Inlet and outlet shut-off valves will make start-up and addition of desiccant easier.

2.4 AFTERFILTER

Van Gas "GF" Series Filters can be installed downstream of the dehydrator to remove particulate contamination from the natural gas. Contact Van Gas for details.

2.5 DRAIN VALVE

Install a drain valve (not furnished with dehydrator) in the drain

coupling at the bottom of the tower (except on PLD8-2.8). A oat/

auto drain valve system is available. Contact Van Gas for details.

PAGE 3

Page 4

2.6 INSTALLING DESICCANT

IMPORTANT

DEPRESSURIZE DEHYDRATOR COMPLETELY BEFORE ATTEMPTING TO REMOVE FILL COVER.

FIGURE 2-B DIMENSIONS

Open ll cover and add the proper amount of pre-bed material and desiccant to ll the dehydrator to the MAXIMUM LEVEL; then level

off the top off the bed. (Reference SECTION 4.3 for desiccant installation instructions)

USE VAN GAS ABSORBENT DESICCANT ONLY!

Close ll cover. Make sure that the inlet and outlet shut-off

valves, and manual drain valve are closed.

MODEL

PLD 8-2.8

PLD 12-2.8

PLD 16-2.8

PLD 20-2.8

PLD 24-2.8

PLD 30-2.8

PLD 36-2.8

PAGE 4

Overall

Height

47-1/4"

73-13/16"

74-1/8"

76-5/8"

74"

80-3/16"

81-3/16"

DRYER DIMENSIONS-INCHES

Inlet

Height

13"

30"

25-3/8"

30"

29-5/16"

Outlet

Height

36"

58"

52-7/8"

57-1/2"

56-13/16"

In to Out

Width

13-1/8"

18"

21-1/4"

23"

36"

42"

48-3/4"

Outside

8-5/8"

12-3/4"

36-3/4"

Dia.

16"

20"

24"

30"

Float

Height

N/A

25"

20-3/8"

25"

24-5/16"

Drain

Height

2-7/16"

14"

13-5/8"

11-5/8"

6-1/8"

9-1/4"

6-7/8"

Inlet

/Outlet

2" NPT

3" RF FLG 150#

Drain

1" NPT

2" NPT

Hammer

Union

Page 5

3.0 OPERATION

3.1 START-UP

Close dehydrator drain valve. See Figure 2-A Recommended Installation.

SLOWLY pressurize by opening the inlet shutoff valve (if installed).

Open the outlet shutoff valve (if installed) slowly to place dehydrator on stream.

CAUTION

Make sure that the dehydrator is not subjected

to sudden ow surges. Always open valves slowly to permit a gradual equalization of pressure between the dehydrator and the gas

supply lines.

4.0 MAINTENANCE

4.1 MAINTENANCE

WARNING IF DRYER IS NOT DRAINED REGULARLY, FLOODING WILL OCCUR AND ACCUMULATED LIQUID MAY ENTER SYSTEM AND DAMAGE DOWNSTREAM EQUIPMENT.

4.2 INSPECT DESSICCANT BED LEVEL

Check bed level monthly until the actual usage rate is determined.

During the drying process, the desiccant tablets dissolve slowly. More tablets must be added to the supply when the top of the bed drops to the MINIMUM LEVEL. The consumption rate is dependent upon

several factors, such as inlet temperature and ow. In Section 4.5,

DESICCANT CONSUMPTION, are several charts showing desiccant consumption rates. Use the charts to determine an approximate usage rate for your application.

NOTE

Use VAN GAS desiccants only. Filling dryer with any other material will void the warranty.

4.3 ADDITION OF DESICCANT

Close dryer inlet and outlet shut-off valves (If installed). Open drain valve and allow dryer to depressurize completely.

Use a solution of soapy water to check all pipe and tting

connections made during installation for leaks. If any leaks are present, immediately depressurize the system and remedy the problem before continuing operation.

3.2 SHUTDOWN

Before shutdown, use the manual drain valve to remove any liquid

that has accumulated in the sump area of the vessel.

Close dryer inlet and outlet shutoff valves (if installed). Open drain valve to depressurize the vessel.

Remove the ll cover.

Using the chart in Figure 4-A, determine the proper quantity of

prebed.

Place the prebed into the dehydrator rst. Level off the prebed.

Again using the chart in Figure 4-A determine the correct quantity

and type of desiccant required to ll the dehydrator.

Slowly pour the desiccant into the dehydrator. Level off the desiccant bed. The desiccant level should NOT be higher than the OUTLET screen.

Replace the ll cover.

WARNING

WHEN HATCH COVER IS REMOVED TO ADD DESICCANT, ALWAYS CHECK O-RING FOR SIGNS OF WEAR.

CHECK COVER FOR RUST, CORROSION OR DAMAGE; REPLACE AS NEEDED.

SEE SECTION 6 FOR REPLACEMENT PARTS.

WARNING COMPLETELY DEPRESSURIZE DRYER BEFORE ATTEMPTING TO REMOVE FILL COVER.

Close the drain valve.

Slowly open the inlet shut-off valve (if installed) to pressurize the dehydrator.

Open the outlet shut-off valve (if installed) and place the dehydrator

on stream.

PAGE 5

Page 6

FIGURE 4-A BED LEVEL DETAIL

DRYER DIMENSIONS-INCHES

MODEL

PLD 8-2.8

PLD 12-2.8

PLD 16-2.8

PLD 20-2.8

PLD 24-2.8

PLD 30-2.8

PLD 36-2.8

Dim. To

Grid

29-1/2"

36-1/2"

37-1/8"

39-3/8"

40-3/8"

41-7/8"

43-5/8"

Dim. To

Pre-Bed

23-1/2"

30-1/2"

31-1/8"

33-3/8"

34-3/8"

35-7/8"

37-5/8"

Dim. To

MIN LEVEL

15-1/2"

14-1/2"

15-1/8"

17-3/8"

18-3/8"

19-7/8"

21-5/8"

Dim. To

MAX LEVEL

12-1/4"

7-1/2"

7-3/8"

9-3/8"

10-3/8"

11-7/8"

13-5/8"

MODEL

PLD 8-2.8

PLD 12-2.8

PLD 16-2.8

PLD 20-2.8

PLD 24-2.8

PLD 30-2.8

PLD 36-2.8

PRE-BED

CERAMIC

BEAD

17 LBS

38 LBS

59 LBS

91 LBS

133 LBS

212 LBS

318 LBS

DRYING

GASDRY

PRIME

25 LBS

115 LBS

187 LBS

291 LBS

425 LBS

678 LBS

1018 LBS

DRYING

GASDRY

PEAK

19 LBS

88 LBS

143 LBS

222 LBS

324 LBS

518 LBS

778 LBS

4.4 BED LEVEL GUIDE

The level of the desiccant bed should be maintained as close to

the MAXIMUM level as possible. The bed level should not be

allowed to fall below the MINIMUM level. Dehydrator performance

will be effected. Reference Figure 4-A for levels and quantities.

With the ll port cover removed, use a measuring stick to determine the distance from the top of the ll opening to the top of the desiccant bed. Reference Figure 4-A. Add desiccant as required

to bring desiccant bed to maximum level.

CAUTION

Never ll the vessel above the MAXIMUM LEVEL.

Filling the vessel above the MAXIMUM level may effect the performance of the dehydrator.

The desiccant bed level should be checked regularly. Section

4.4 DESICCANT CONSUMPTION will help you estimate the amount of desiccant that the dehydrator should use based on operating conditions.

4.5 DESICCANT CONSUMPTION

Consumption rate based on average conditions. Actual conditions can vary.

4.5-A GASDRY PRIME DESICCANT

This general purpose tablet is recommended for installations where inlet gas temperature is 100oF or lower. Depending on the pressure and temperature, GasDry Prime can provide a residual

moisture content below 19 lbs/mmscf.

DRYING

GASDRY

MAX

21 LBS

96 LBS

156 LBS

243 LBS

354 LBS

565 LBS

848 LBS

Chart 1 shows the level of dryness that GasDry Prime will provide at different conditions.

Chart 2 shows an approximate consumption rate for GasDry Prime at several conditions. Use the charts for guidelines to calculate the approximate consumption rate of the desiccant.

CHART 1

MOISTURE CONTENT OF GAS (LBS. H2O/MMSCF) AFTER DEHYDRATOR WITH GASDRY PRIME

INLET TEMP

100oF

95oF

90oF

85oF

80oF

75oF

70oF

65oF

60oF

55oF

50oF

PSIG

391.8

336.5

288.9

246.5

210.2

178.1

150.3

126.9

106.9

89.0

74.4

100

PSIG

224.7

193.1

165.9

141.6

120.8

102.5

86.6

73.2

61.7

51.4

43.0

150

PSIG

159

136.7

117.6

100.4

85.7

72.8

61.5

52.0

43.9

36.7

30.7

175

PSIG

139.2

119.7

103.0

87.9

75.1

63.8

53.9

45.7

38.6

32.2

27.0

200

PSIG

124.0

106.6

91.7

78.4

67.0

56.9

48.2

40.8

34.4

28.8

24.1

250

PSIG

102.1

87.9

75.7

64.7

55.3

47.0

39.8

33.8

28.5

23.9

20.0

280

PSIG

92.6

79.8

68.7

58.7

50.2

42.7

36.2

30.7

26.0

21.7

18.2

PAGE 6

NOTE MMSCF is 1,000,000 STANDARD CUBIC FEET

Page 7

CHART 2

GASDRY PRIME CONSUMPTION RATE (LBS./MMSCF)

INLET TEMP

100oF

95oF

90oF

85oF

80oF

75oF

70oF

65oF

60oF

55oF

50oF

PSIG

71.2

61.2

52.5

44.8

38.2

32.4

27.3

23.1

19.4

16.2

13.5

100

PSIG

40.9

35.1

30.2

25.8

22.0

18.6

15.7

13.3

11.2

9.4

7.8

150

PSIG

28.9

24.9

21.4

18.3

15.6

13.2

11.2

9.5

8.0

6.7

5.6

175

PSIG

25.3

21.8

18.7

16.0

13.7

11.6

9.8

8.3

7.0

5.9

4.9

200

PSIG

22.5

19.4

16.7

14.3

12.2

10.4

8.8

7.4

6.3

5.2

4.4

250

PSIG

18.6

16.0

13.8

11.8

10.1

8.6

7.2

6.1

5.2

4.3

3.6

280

PSIG

16.8

14.5

12.5

10.7

9.1

7.8

6.6

5.6

4.7

4.0

3.3

4.5-B GASDRY PEAK DESICCANT

The general purpose tablet is reccommended for installations where inlet gas temperature is 80oF or lower. Depending on the pressure and temperature, GasDry Peak can provide a residual moisture content

below 10 lbs/MMSCF.

Chart 3 shows the level of dryness that GasDry Peak provides at different conditions.

Chart 4 shows an approximate consumption rate for GasDry Peak at several conditions. Use the charts for guidelines to calculate the approximate consumption rate of the desiccant.

CHART 3

MOISTURE CONTENT OF GAS (LBS. H2O/MMSCF) AFTER DEHYDRATOR WITH GASDRY PEAK

INLET TEMP

80oF

75oF

70oF

65oF

60oF

55oF

50oF

45oF

CHART 4

PSIG

126.1

106.9

90.2

76.1

64.1

53.4

44.6

37.0

100

PSIG

72.5

61.5

51.9

43.9

37.0

30.9

25.8

21.5

150

PSIG

51.4

43.7

36.9

31.2

26.3

22.0

18.4

15.3

175

PSIG

45.1

38.3

32.4

27.4

23.1

19.3

16.2

13.5

200

PSIG

40.2

34.2

28.9

24.5

20.7

17.3

14.5

12.0

250

PSIG

33.2

28.2

23.9

20.3

17.1

14.3

12.0

10.0

280

PSIG

30.1

25.6

21.7

18.4

15.6

13.0

10.9

9.1

GASDRY PEAK CONSUMPTION RATE (LBS./MMSCF)

INLET TEMP

80oF

75oF

70oF

65oF

60oF

55oF

50oF

45oF

PSIG

116.4

98.6

83.2

70.3

59.2

49.3

41.2

34.2

100

PSIG

66.9

56.7

47.9

40.5

34.1

28.5

23.8

19.8

150

PSIG

47.5

40.3

34.1

28.8

24.3

20.3

17.0

14.1

175

PSIG

41.6

35.3

29.9

25.3

21.3

17.8

14.9

12.4

200

PSIG

37.1

31.5

26.7

22.6

19.1

15.9

13.3

11.1

250

PSIG

30.6

26.0

22.0

18.7

15.8

13.2

11.1

9.2

280

PSIG

27.8

23.7

20.0

17.0

14.4

12.0

10.1

8.4

4.5-B GASDRY MAX DESICCANT

Where extremely dry gas is required or where operating pressure is

low, GasDry Max tablets provide a lower residual moisture content.

Chart 5 shows the level of dryness that GasDry Max will provide at different conditions.

Chart 6 shows an approximate consumption rate for GasDry Max

at several conditions. Use the charts for guidelines to calculate the approximate consumption rate of the desiccant.

CHART 5

MOISTURE CONTENT OF GAS (LBS.H2O/MMSCF) AFTER DEHYDRATOR WITH GASDRY MAX

INLET TEMP

100oF

95oF

90oF

85oF

80oF

75oF

70oF

65oF

60oF

55oF

50oF

45oF

40oF

CHART 6

PSIG

92.6

79.5

68.3

58.3

49.7

42.1

35.5

30.0

25.3

21.0

17.6

14.6

12.1

100

PSIG

53.1

45.6

39.2

33.5

28.6

24.2

20.5

17.3

14.6

12.2

10.2

8.5

7.0

150

PSIG

37.6

32.3

27.8

23.7

20.3

17.2

14.5

12.3

10.4

8.7

7.3

6.0

5.0

175

PSIG

32.9

28.3

24.3

20.8

17.8

15.1

12.8

10.8

9.1

7.6

6.4

5.3

4.4

200

PSIG

29.3

25.2

21.7

18.5

15.8

13.5

11.4

9.6

8.1

6.8

5.7

4.7

3.9

250

PSIG

24.1

20.8

17.9

15.3

13.1

11.1

9.4

8.0

6.7

5.6

4.7

3.9

3.3

280

PSIG

21.9

18.9

16.2

13.9

11.9

10.1

8.6

7.3

6.1

5.1

4.3

3.6

3.0

GASDRY MAX CONSUMPTION RATE (LBS./MMSCF)

INLET TEMP

100oF

95oF

90oF

85oF

80oF

75oF

70oF

65oF

60oF

55oF

50oF

45oF

40oF

PSIG

206.6

177.4

152.3

130.0

110.8

93.9

79.3

66.9

56.3

47.0

39.2

32.5

26.9

100

PSIG

118.5

101.8

87.5

74.7

63.7

54.0

45.6

38.6

32.5

27.1

22.7

18.9

15.6

150

PSIG

83.8

72.1

62.0

53.0

45.2

38.4

32.5

27.4

23.1

19.3

16.2

13.5

11.1

175

PSIG

73.4

63.1

54.3

46.4

39.6

33.6

28.4

24.1

20.3

17.0

14.2

11.8

9.8

200

PSIG

65.4

56.2

48.4

41.4

35.3

30.0

25.4

21.5

18.2

15.2

12.7

10.6

8.8

250

PSIG

53.9

46.4

39.9

34.1

29.2

24.8

21.0

17.8

15.1

12.6

10.6

8.8

7.3

280

PSIG

48.8

42.1

36.2

31.0

26.5

22.5

19.1

16.2

13.7

11.5

9.6

8.0

6.7

NOTE MMSCF is 1,000,000 STANDARD CUBIC FEET

PAGE 7

Page 8

5.0 TROUBLESHOOTING CHECK LIST

If liquid water is detected downstream or if desiccant consumption seems excessively high, the most likely causes are as follows:

Problem

Possible Cause

Liquid downstream The frequency of draining is not adequate.

Check inlet Temperature. Conditions may have changed. Determine the cause.

High inlet temperature

Low desiccant

If gas is compressed mechanically, check compressor aftercooler.

Check bed level to make sure that desiccant tablet level has not dropped below minimum level.

level

Incorrect flow

and/or pressure

Contaminated Desiccant bed

If correcting conditions in the troubleshooting check list does not remedy the problem, consult your local VAN GAS Distributor or call the

VAN GAS factory in Lake City, Pennsylvania (888)-606-9303 or (814)-774-2636.

Check ow through dehydrator, refer to chart on page 2.

Check inlet pressure.

Inspect condition of desiccant. If discolored (deep yellow or brown), it may be contaminated.

A heavily contaminated desiccant bed must be replaced to return dehydrator to optimum performance.

6.0 REPLACEMENT PARTS LIST

DESICCANTS

CERAMIC BEAD (PREBED)

DESCRIPTION PART NO. 90 LB. CARTON 33-0281

GASDRY PRIME(DRYING)

DESCRIPTION PART NO.

50 LB. PAIL 33-0355 50 LB. BAG 33-0354

GASDRY PEAK(DRYING)

DESCRIPTION PART NO.

45 LB. PAIL 33-0328 50 LB. BAG 33-0205 400 LB. DRUM 33-0283

PLD 8, PLD 12, AND PLD 16 DEHYDRATOR

DESCRIPTION PART NO.

BLIND PLATE 26-7126 HAMMER UNION NUT 26-7128 FILL COVER O-RING 26-7573

PLD 20, PLD 24, AND PLD 36 DEHYDRATOR

DESCRIPTION PART NO.

BLIND PLATE 26-7127 HAMMER UNION NUT 26-7129 FILL COVER O-RING 26-3640

DESCRIPTION PART NO

7 LB. PAIL 33-0318 25 LB. PAIL 33-0232

GasDry Prime, GasDry Peak, and GasDry Max are the registered trade names of chemical drying agents specically formulated by and

for VAN GAS Single Tower Dehydrators.

GASDRY MAX (DRYING)

2950 Mechanic Street

Lake City, Pa 16423 USA



Phone: 800-840-9906

Fax: 814-774-0778

www.vangastech.com