Cashco DA4 User Manual

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INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)

MODEL DA4

(Formerly DA3/4)

DIRECT-ACTING, PRESSURE LOADED

PRESSURE REDUCING REGULATOR

(Model DA3 was identical to DA4 except that the DA3 did not include a lower return spring.)

SECTION I

I. DESCRIPTION AND SCOPE

Model DA4 is a pressure reducing regulator used to control downstream (outlet or P2) pressure. Sizes are 1/2" (DN15), 3/4" (DN20), 1" (DN25), 1-1/4" (DN32), 1-1/2" (DN40), 2" (DN50), 3" (DN80) and 4" (DN100). With proper trim uti li za tion, the unit is suitable for liquid, gaseous, or steam service. Refer to Technical Bulletin DA4-TB for design conditions and selection recommendations. (NOTE: This product was formerly identiﬁ ed as a Model

D4; a Model DA4 and D4 are one and the same product.)

This manual does not include instructions related to the various methods of pressure loading a Model DA4 main valve.

SECTION II

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11-13

II. REFERENCES

Refer to Technical Bulletin DA4-TB for tech ni cal

speciﬁ cations for this reg u la tor.

SECTION III

III. INSTALLATION

CAUTION

For welded installations, all internal trim parts, seals and diaphragm(s) must be removed from reg u la tor body prior to welding into pipeline. The heat of fusion welding will dam age non-metallic parts if not re moved. NOTE: This does not apply to units equipped with extended pipe nip ples.

1. Regulator may be rotated around pipe axis 360

degrees. For ease of maintenance, the rec om mend ed position is with the cover dome (25) up wards. In liquid service it is recommended that the cover dome (25) be oriented down wards, and that a cus tom er supplied and installed vent valve be pro vid ed at the external sensing connection to bleed-off trapped gas/air under the diaphragm.

2. Provide space below, above, and around reg u la-

tor for removal of parts during maintenance.

3. Install block valves and pressure gauges to pro-

vide means for adjustment, operation, bypass, or removal of the regulator. A pipeline strainer is recommended before inlet to remove typical pipe line debris from entering valve and damaging internal “soft goods”, primarily the dynamic seal.

ABBREVIATIONS CW – Clockwise CCW – Counter Clockwise ITA – Inner Trim Assembly

CAUTION

Installation of adequate overpressure pro tec tion is recommended to pro tect the reg u la tor from overpressure and all down stream equip ment from damage in the event of regulator failure.

4. Downstream Sensing Installation Considerations – Internal or External Sensing: a. The regulator may be installed with internal or

external sensing. Unless otherwise spec i ﬁ ed, the regulator is supplied by factory with internal sensing. The regulator may be con vert ed in the ﬁ eld to external sensing. (See Section VII Maintenance, Part H – Converting Internal/ External Sensing.

b. Reference DA4-TB, Table DAG-11 for rec om-

men da tions for applying external pressure sensing.

c. For internal sensing, no external line is re-

quired. For external sensing, use an external control line. The line is connected from the 1/4" (DN8) NPT tap (Port 5 – See Fig. 6) on the side of the body di a phragm ﬂ ange to a pressure tap down stream of the regulator.

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Use 1/4" or 3/8" (DN8 or 10) outer di am e ter tubing or 3/8" (DN10) pipe having an inner di am e ter equiv a lent to Schedule 40 pipe.

d. For condensable vapors (i.e. steam) slope the

external sensing line downward 2 to 5 de grees to outlet piping to prevent water pock ets, which allows the diaphragm chamber to always be self draining. The external sensing line may be sloped upward for liquids or gas es.

CAUTION

DO NOT HYDROSTATIC TEST THROUGH AN IN STALLED UNIT; ISOLATE REGULATOR FROM TEST. The "OUTLET RATING" as printed on the name plate is the rec om mend ed “upper op er at ing limit” for the sens ing di a phragm. Higher pres sures could cause internal dam age. In ad di tion, note on the nameplate that the Inlet and Outlet pres sure and temperature ratings are at different levels.

IV. PRINCIPLE OF OPERATION

1. When a loading pressure – P the top side of a diaphragm, the outlet controlled pressure – P

– will balance at approximately

.90 – .98 of the loading pressure - PL. (NOTE:

Fluc tu a tions in P1 – Inlet Pressure will cause a deviation in P

– Outlet Pressure due to inverse

sym pa thet ic ratio effect.) See Section VIII.

2. Movement occurs as pressure variations register on the diaphragm. The registering pressure is the outlet, P

, or downstream pressure. The loading

– is applied to

Load

CAUTION

Installation of adequate overpressure pro tec tion is recommended to pro tect the reg u la tor from over pres sure and all down stream equip ment from dam age in the event of regulator failure.

Model DA4

SECTION IV

pressure ﬂ uid op pos es di a phragm move ment. As outlet pres sure drops, the loading pressure push es the di a phragm down, opening the port; as outlet pres sure increases, the diaphragm pushes up and the port opening closes.

3. A diaphragm failure will tend to cause the reg u la tor to fall below setpoint. A loss of loading pres sure while inlet pressure is imposed will cause the regulator to fail close. A com plete diaphragm failure will cause the inlet process ﬂ uid to mix with the loading ﬂ uid.

V. STARTUP

1 Start with the block valves closed.

2. Adjust the loading system pressure control de vice so that main regulator is trying to be con trolled at 0 psig pressure.

3. If it is a “hot” piping system, and equipped with a bypass valve, slowly open the bypass valve to preheat the system piping and to allow slow ex pan sion of the piping. Ensure proper steam trap operation if installed. Closely monitor outlet (down stream) pressure via gauge to ensure not over-pressurizing. NOTE: If no bypass valve is

CAUTION

Do not walk away and leave a bypassed reg u la tor unattended!

SECTION V

in stalled, extra caution should be used in starting up a cold system; i.e. do everything slowly.

4. Crack open the outlet (downstream) block valve to approximately 10% full open.

5. Slowly open the inlet (upstream) block valve to about 25% open. Adjust the loading system pres sure control device setpoint pressure upwards until the main valve is ﬂ owing. Observe the outlet pressure gauge to ensure not overpressurizing.

6. Continue to slowly open the inlet (upstream) block valve until fully open.

7. Continue to slowly open the outlet (downstream) block valve, especially when the downstream piping system isn’t pressurized. If the outlet (down stream) pressure exceeds the desired pres sure, close the inlet block valve and go to Step 2. Close bypass valve approximately 25%, and re peat pro ce dure.

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8. When ﬂ ow is established steady enough that the outlet (downstream) block valve is fully open, begin to slowly close the bypass valve if installed.

9. Develop system ﬂ ow to a level near its expected normal rate, and reset the regulator set point by adjusting the loading system pressure control setpoint to the desired outlet pressure level.

VI. SHUTDOWN

10. Reduce system ﬂ ow to a minimum level and observe pressure set point. Outlet pressure will rise from the set point of Step 9 for a Model DA4. The max i mum rise in outlet pres sure on de creas ing ﬂ ow should not exceed the 10%. If it does, consult factory.

SECTION VI

1. Shutoff auxiliary loading pressure source, if sup plied.

2. Shutoff inlet block valve.

3. Allow sufﬁ cient time for the line pressure down- stream of the inlet block valve to bleed down.

SECTION VII

VII. MAINTENANCE

A. General:

WARNING

SYSTEM UNDER PRESSURE. Prior to per form ing any maintenance, isolate the reg u la tor from the system and relieve all pressure. Failure to do so could result in personal injury.

1. The regulator may be serviced without re mov ing the regulator from pipeline. The reg u la tor is designed with quick-change trim to simplify maintenance.

2. Record the nameplate information to req ui si tion repair parts for the regulator. The in for ma tion should include: size, KM Product Code, Serial Number, and internal or ex ter nal sens ing. (NOTE: Never both types of sens- ing.) If external sensing is used, be sure that the external sensing line is connected.

3. Refer to Section X for recommended repair parts. Only use original equipment parts sup plied by Cashco/KM for re build ing or re pair ing reg u la tors.

4. Owner should refer to owner's procedures for removal, handling, cleaning and disposal of nonreuseable parts, i.e. gaskets, etc.

NOTE: On regulators originally supplied

as “oxygen clean” – Opt-55, maintenance must include a level of cleanliness equal to Cashco cleaning standard #S-1134.

4. Shutoff the outlet block valve.

5. Relieve the trapped upstream and downstream pressure and loading pres sure.

6. The regulator may now be removed from the pipe line or disassembled for inspection and pre ven ta tive main te nance while in-line.

5. The Inner Trim is re moved and replaced in the body ( 23) as an assemblage of parts. The Inner Trim Assembly, here in af ter called

ITA, consists of the following parts:

Item Dynamic No. Seal Type Part Description

13 ..................... All ..........................Guide Bearing/Piston

14 .....................All ................................. Static Stem Seal

14.1 ............... All ...................... Upper Static Stem Seal

14.2 ............... All ......................Middle Static Stem Seal

14.3 ............... All ...................... Lower Static Stem Seal

15 .....................All ................................ Cage O-ring Seal

16 .................CW,PW .............................................. Wiper

17.1 ..............CW,PW .................................Wiper Washer

17.2 ........... OR,CP,PR ........ Camber Adjusting Washer *

17.3.................. UC.......................................Seal Retainer

19 ..................... All ................................................... Cage

20 ..................... All ...........................................Valve Plug

21 ..................... All ............................................ Seat Ring

27 .....................All ............................. Dynamic Side Seal

27.1 ........... CP,CW ................................. TFE Cap Seal

27.2 ...........CP, CW ..................... O-ring Energizer/Seal

27.3 .............. UC .......... U-Cup Seal w/Metal Energizer

27.4 .............. OR ....................................... O-Ring Seal

27.5 ........... PR,PW ............................. Piston Ring Seal

27.6 ........... PR,PW ............. Piston Ring SST Energizer

* Metal Diaphragm Only.

A detailed view of the dynamic side seal parts

is shown in Figure 1 on the next page.

6. Sub-Sections B. through F. are for con struc tions that do NOT include any Opt-81 High Outlet Pressures with di a phragm support. These con struc tions are cov ered in SubSec tion G.

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Type OR — O-Ring

Dynamic Seal

Type PR — PRA

Dynamic Seal

Type CP— TFE Cap

Dynamic Seal

Type CW — TFE Cap Dynamic Seal + Wiper

Type PW — PRA Dy nam ic

Seal + Wiper

Type UC — U-Cup

Dynamic Seal

SECTION "A"

Figure 1: Dynamic Side Seals

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B. Main Valve Disassembly:

12. Remove the ITA by pulling up on the valve plug (20). Set ITA aside.

WARNING

SYSTEM UNDER PRESSURE. Prior to per form ing any maintenance, isolate the reg u la tor from the system and relieve all pressure. Failure to do so could result in personal injury.

1. Shut down system in accordance Section VI.

2. Disconnect the external sensing line, if in stalled.

3. Though it is possible to disassemble the valve unit while installed in a pipeline, it is rec om mend ed that maintenance be done in a shop when possible. The descriptions hereafter will assume shop disassembly. Remove valve from pipeline.

4. Place the valve unit in a vise with the cover dome (25) upwards.

5. Loosen the diaphragm ﬂ ange bolts (11) and nuts (12) uniformly.

6. Place matchmarks on body (23) and cover dome (25) ﬂ anges. Remove cover dome (25).

7. For composition diaphragm construction, hold the milled “ﬂ ats” on top of the valve plug (20) stationary. Loosen and remove the di a phragm lock nut (7). NOTE: Metal di a phragm con struc-

tions do NOT have a di a phragm lock nut (7).

8. Remove upper diaphragm pressure plate (8).

9. Remove diaphragm(s) (9, 9.1, 9.2, 9.9) and o-ring upper stem seal (14.1). Examine diaphragm(s) to determine whether failed; determine if op er at ing conditions are ex ceed ing pressure, pressure drop or temperature limits.

10. For composition diaphragm construction, re move lower diaphragm pusher plate (10).

11. Evenly loosen the three cage cap screws (18) in single revolution increments. Regulator may con tain a lower piston spring (22); the ITA should rise as the cage cap screws (18) are evenly backed out. A down wards holding force should be ap plied to the top of the piston-guide bearing (13) to pre vent the ITA from pop ping up as the last threads of the cage cap screws (18) are backed out.

13. Remove the lower piston spring (22), as ap pli ca ble, from within the body (23).

14. Remove o-ring cage seal (15).

15. If supplied, remove internal sensing drilled plug (32) using 5/32" (4 mm) Allen wrench.

16. Remove body (23) from vise. Clean all re us able metal parts according to owner's pro ce dures.

C. Disassembly of the ITA:

1. Units with Composition Diaphragm(s) (See Figure 2): a. Pull the valve plug (20) down wards and

out of the piston-guide bear ing (13) and out of the cage's (19) bottom, while hold ing the cage (19).

b. Remove the piston-guide bearing (13)

from the upper end of the cage (19).

14.2

14.3

Figure 2: Assembled ITA,

Composition Di a phragm Construction

c. Remove o-ring middle stem seal (14.2)

from piston-guide bearing (13).

d. Examine the com po nents (27.1, 27.2,

27.3, 27.4, 27.5, 27.6) of the dy nam ic side seal (27) mechanism to de ter mine if sig niﬁ cant leakage was oc cur ring. If the dy nam ic side seal (27) shows signs of sig niﬁ cant leakage, de ter mine if op er at- ing con di tions are ex ceed ing pres sure, pres sure drop, or tem per a ture limits.

Remove dynamic side seal (27) com po-

nents. Special care should be taken when using “tools” to remove the components

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to ensure that no scratches are imparted to any portion of the piston-guide bearing (13) groove.

e. Remove wiper seal (16), if supplied, from

within cage (19).

f. Remove wiper washer (17.1) or camber

adjusting washer (17.2), if supplied, from within cage (19).

g. Remove o-ring lower stem seal (14.3)

from plug (20).

h. Remove seat ring (21); examine for signs

of leakage. If seat ring (21) shows signs of signiﬁ cant leakage, determine if op er at ing con di tions of pressure, pressure drop, or temperature are ex ceed ing limits.

2. Units with Metal Diaphragm(s) (See Fig 3): a. To disassemble the ITA, hold the lower

part of the valve plug (20) in a bench vise; do not hold on the machined sur face in the plug's (20) spindle area. (The spin dle “slides” in the pressed-in-place lower guide bushing (24) and can not be al lowed to be marred.)

b. Using a special double-posted spanner

wrench ﬁ tting (to order see NOTE in Section X, Parts Ordering Information), turn the piston-guide bear ing (13) CCW to loos en; pis ton-guide bear ing (13) can be re moved by hand after loos en ing.

c. Pull the valve plug (20) downwards out

of the piston-guide bearing (13) and out thru the bottom of the cage (19).

Figure 3: Assembled ITA,

Metal Diaphragm Construction

d. Remove the piston-guide bearing (13)

from the upper end of cage (19).

e. Examine the com po nents (27.1, 27.2,

pres sure drop, or tem per a ture lim its.

Remove dynamic side seal (27) com po-

nents and discard. Special care should be taken when using “tools” to remove the components to ensure that no scratches are imparted to any portion of the pistonguide bearing (13) groove.

f. Remove wiper seal (16), if supplied, from

within cage (19).

g. Remove wiper washer (17.1) or camber

adjusting washer (17.2), if supplied, from within cage (19).

h. Remove o-ring lower stem seal (14.3)

from plug (20).

i. Remove seat ring (21); examine for signs

of leakage. If seat ring (21) shows signs of signiﬁ cant leakage, determine if op er at ing con di tions of pressure, pressure drop, or temperature are ex ceed ing limits.

3. Clean all reusable metal parts according to owner's procedures.

D. Inspection of Parts:

1. After inspection remove from the work area and dis card the old “soft goods” parts (i.e. orings, di a phragms, seals, gaskets, etc.) after in spec tion. These parts MUST be re placed with fac to ry supplied new parts.

2. Inspect the metal parts that will be reused. The parts should be free of surface con tam i nants, burrs, oxides, and scale. Rework and clean parts as necessary. Surface con di tions that affect the regulator performance are stated below; replace parts that can not be re worked or cleaned.

3. QC Requirements: a. Valve plug (20);

1. 16 rms ﬁ nish on its seating surface for tight shutoff.

2. No major defects on bottom guide spin dle.

b. Cage (19);

1. 16 rms ﬁ nish on cylinder bore. No “ledges” formed due to wear from moving dynamic side seal (27) or wiper seal (16).

c. Lower guide bushing (24) (non-re place-

able):

1. 16 rms ﬁ nish on bore.

2. Max 0.015 inch (0.38 mm) clearance be tween valve plug (20) spindle and lower guide bushing (24).

d. Internal sensing drilled plug (32);

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1. Ensure that bore is minimum 0.125 inch (3.20 mm). Drill out as required.

4. Staging Material for Reassembly. a. Inspect and clean parts, as necessary,

from the spare parts kit. (See Article VII .A.4. comments concerning cleaning for ox y gen service.)

b. Lay out all the regulator parts and check

against the bill of material.

E. Reassembly of the ITA:

“cut” o-ring energizer/seal (27.2). Using thumbs, work the o-ring en er giz er/ seal (27.2) up and into the groove of

Not supplied. Use any bolt, washers (2) and nut of same approximate hole size.

1. When replacing the optional wiper seal (16), the replacement wiper seal (16) is “preformed”. It may, however, require reforming. Under normal circumstances, this step may not be required. If needed, reform the wiper seal (16) by press ing the temporary assembly parts into the cage (19) backwards as shown in Figure 4. The wiper seal (16) is best left in this position overnight (minimum of two (2) hours) prior to re as sem bly.

2. After forming the wiper seal, remove parts (13, 16, 17) from cage (19) and disassemble the tem po rary assembly of Step 1. above.

3. Installation of dynamic side seal (27) (See Figure 1): a. Type OR:

1. Stretch o-ring seal (27.4) over lower cir cum fer ence of piston-guide bear ing (13), tak ing care not to “cut” o-ring seal (27.4). Using thumbs, work the o-ring seal (27.4) up and into the groove of the piston-guide bearing (13). NOTE: A very slight amount

of ﬂ uid and elas tomer compatible lu bri cant is rec om mend ed as an in stal la tion aid.

2. For metal diaphragm construction,

insert cam ber adjusting washer (17.2) into cage (19) and allow to rest in the bottom of the cage (19).

3. Position piston-guide bearing (13) over upper end of cage (19) properly oriented. Using thumbs, evenly press piston-guide bearing (13) into the cage (19), ensuring not to “cut” o-ring seal (27.4). Continue pressing pis ton-guide bearing (13) until in ap prox i mate ﬁ nal position.

b. Type CP:

1. Stretch o-ring energizer/seal (27.2) over low er cir cum fer ence of pistonguide bear ing (13), tak ing care not to

Figure 4: Temporary Assembly Parts

bear ing (13). NOTE: A very slight

amount of ﬂ uid and elas tomer com- patible lu bri cant is rec om mend ed as an in stal la tion aid.

2. For metal diaphragm construction, insert cam ber adjusting washer (17.2) into cage (19) and allow to rest in the bottom of the cage (19).

3. Position TFE cap seal (27.1) ring with rectangular cross-section at end of pis ton-guide bearing (13). Stretch cap seal (27.1) over lower end of pistonguide bear ing (13) using thumbs to work the cap seal (27.1) onto the piston-guide bearing (13). DO NOT USE A TOOL FOR THIS STEP. Con tin ue pressing cap seal (27.1) up wards towards the groove until the cap seal (27.1) “snaps” into the groove of the piston-guide bearing (13).

4. Position piston-guide bearing (13) over and into upper end of cage (19) until the cap seal (27.1) edge touches the upper lip of the cage (19). While gently applying force to press the piston-guide bushing (13) into the cage (19), simultaneously use ﬁ n gers to lightly press the cap seal (27.1) inwards into the groove of the pis tonguide bearing (13) until the cap seal (27.1) “slips into” the cage (19). DO NOT USE TOOLS, LU BRI CANT, OR HEAVY FORCE TO EN GAGE THE CAP SEAL (27.1) INTO THE CAGE (19). Do not press in wards on the Cap Seal (27.1) too much or the cap seal (27.1) may slide out of its groove or the cap seal (27.1) can be damaged.

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c. Type CW:

1. Stretch o-ring energizer/seal (27.2) over low er cir cum fer ence of pistonguide bear ing (13), tak ing care not to “cut” o-ring energizer/seal (27.2). Using thumbs, work the o-ring en er giz er/seal up and into the groove of the bear ing (13). NOTE: A very

slight amount of ﬂ uid and elas tomer compatible lu bri cant is rec om mend ed as an in stal la tion aid.

2. Place wiper washer (17.1) into “cup” of Wiper Seal (16). Holding these parts (17.1 & 16) between thumb and foreﬁ nger, in sert into cage (19) at an approximate 45° angled approach with wiper washer (17.1) on bottom, wiper seal (16) on top with turned-down lip of wiper seal (16) en ter ing cage (19) ﬁ rst. Rotate wiper seal (16) and wiper washer (17.1) to a level po si tion approximately half way down into cage (19). Allow wiper washer (17.1) to rest on bottom of cage (19).

3. Position TFE cap seal (27.1) ring with rectangular cross-section at end of pis ton-guide bearing (13). Stretch cap seal (27.1) over lower end of pistonguide bear ing (13) using thumbs to work the cap seal (27.1) onto the bearing (13). DO NOT USE A TOOL FOR THIS STEP. Con tin ue pressing cap seal (27.1) up wards towards the groove until the cap seal (27.1) “snaps” into the groove of the pistonguide bearing (13).

d. Type PR:

1. Stretch corrugated metal piston ring en er giz er (27.6) over lower cir cum fer ence of piston-guide bearing (13). Using thumbs work the energizer (27.6) into the bearing (13) groove.

2. Spread a piston ring seal (27.5) and slide over lower circumference of pis ton-guide bearing (13), taking care not to “cut” piston ring seal (27.5). Using thumbs, work the piston ring seal (27.5) into the groove of the bearing (13). Repeat this procedure with a second piston ring seal (27.5).

NOTE: A piston ring as sem bly (PRA) consists of one metal corrugated energizer (27.6) and two piston ring seals (27.5).

3. Position piston-guide bearing (13) over and into upper end of cage (19) until the lower piston ring seal (27.5) touches the upper lip of the cage (19). While gently applying force to press the piston-guide bearing (13) into the cage (19), si mul ta neous ly use ﬁ n gers to lightly circumferentially press the ﬁ rst (lower) piston ring seal (27.5) inwards into the piston-guide bearing (13) groove until the ﬁ rst piston ring seal (27.5) “slips into” the cage (19). Repeat for the second piston ring seal (27.5).

e. Type PW:

1. Place wiper washer (17.1) into “cup” of Wiper Seal (16). Holding these parts (17.1 & 16) between thumb and foreﬁ nger, in sert into cage (19) at an approximate 45° angled approach with wiper washer (17.1) on bottom, wiper seal (16) on top with turneddown lip of wiper seal (16) en ter ing cage (19) ﬁ rst. Rotate wiper seal (16) and wiper washer (17.1) to a level po si tion approximately half way down into cage (19). Allow wiper washer (17.1) to rest on bottom of cage (19).

2. Stretch corrugated metal piston ring en er giz er (27.6) over lower cir cum fer ence of piston-guide bearing (13). Using thumbs work the energizer (27.6) into the bearing (13) groove.

3. Spread a piston ring seal (27.5) and slide over lower circumference of pis ton-guide bearing (13), taking care not to “cut” piston ring seal (27.5).

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Using thumbs, work the piston ring seal (27.5) into the groove of the bearing (13). Repeat this procedure with a second piston ring seal (27.5).

NOTE: A piston ring as sem bly (PRA) consists of one metal corrugated energizer (27.6) and two piston ring seals (27.5).

4. Position piston-guide bearing (13) over and into upper end of cage (19) until the lower piston ring seal (27.5) touches the upper lip of the cage (19). While gently applying force to press the piston-guide bearing (13) into the cage (19), si mul ta neous ly use ﬁ n gers to lightly circumferentially press the ﬁ rst (lower) piston ring seal (27.5) inwards into the piston-guide bearing (13) groove until the ﬁ rst piston ring seal (27.5) “slips into” the cage (19). Repeat for the second piston ring seal (27.5).

f. Type UC:

1. Stretch u-cup seal (27.3) over lower circumference of piston-guide bear ing (13), taking care not to “cut” u-cup seal (27.3) on the protruding shelf that is part of the piston-guide bear ing's (13) groove. Ensure that the u-cup seal (27.3) is oriented with the center-open-downwards as shown in Figure 1, as the u-cup seal (27.3) depends upon the P1-Inlet Pres sure to pressure activate the seal for proper sealing action.

2. Position piston-guide bearing (13) over and into upper end of cage (19) until the cap seal (27.1) edge touches the upper lip of the cage (19). While gently applying force to press the piston-guide bearing (13) into the cage (19), simultaneously use ﬁ ngers to lightly press the u-cup seal (27.3) inwards into the groove of the pistonguide bearing (13) until the u-cup seal (27.3) “slips into” the cage (19). DO NOT USE TOOLS, LUBRICANT, OR HEAVY FORCE TO ENGAGE THE U-CUP SEAL (27.3) INTO THE CAGE (19).

4. Place properly oriented seat ring (21) onto its shoul der at the lower end of cage (19).

5. Composition Diaphragm Designs: a. Place new o-ring lower stem seal (14.3)

into groove of valve plug (20).

b. Insert valve plug (20) upwards through

lower end of cage (19) and through the center hole in piston-guide bearing (13), also capturing the camber adjusting wash er (17.2) or wiper washer (17.1) and wiper seal (16), if supplied. Hold plug (20) and cage (19) together.

c. Place an oversized nut or stack of wash-

ers, the same approximate height of the up per diaphragm pres sure plate (8) and the lower diaphragm pusher plate (10), over the upper end of valve plug (20) and temporarily secure with diaphragm lock nut (7), manually tightened. Do NOT al low valve plug (20) to rotate against seat ring (21) during tightening.

d. This completes ITA preliminary/partial

reassembly.

6. Metal Diaphragm Designs: a. Insert valve plug (20) upwards through

lower end of cage (19) and through the center hole of camber adjusting washer (17.2) or wiper washer (17.1) and wiper seal (16).

b. Engage valve plug (20) with piston-guide

bearing (13) threads and tighten man u al ly as far as possible.

c. Place ITA into a vise with leaded jaws and

grasp at a hub location on the valve plug (20) that is not in the “spindle” zone. (See Figure 3.)

d. Using a spe cial dou ble-posted span ner

wrench ﬁ t ting (to order see NOTE in Sec- tion X, Parts Ordering Information), tighten piston-guide bear ing (13) to the valve plug (20) with the following torque values. Do NOT allow valve plug (20) to rotate against seat ring (21) during tight en ing.

e. This completes ITA reassembly.

F. Main Reassembly:

1. Place body (23) in a vise.

2. Reinstall internal sensing drilled plug (32) with compatible thread sealant.

3. Insert the lower piston spring (22) into the body (23), if supplied.

4. Fit the o-ring cage seal (15) into its body (23) groove.

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5. With the ITA held manually in the closed po si tion, insert ITA into body (23).

6. Properly align all three cage bolt (18) holes as there is only one circumferential location pos si ble for this align ment. If a lower piston spring (22) is used, apply downward force to the top of the cage (19) until the ITA is lowered suf ﬁ cient ly to engage the cage bolts (18) into the body (23). Engage all of the cage bolts (18), then evenly screw in the cage bolts in one-half revolution increments to pull down the ITA evenly, taking care NOT TO “AN GLE” the ITA in the BODY. Torque the cage bolts (18) to 13-15 ft-lbs (17.6-20.3 N-m).

7. Composition Diaphragm Designs: a. For the following steps b.– h., the upper

end of valve plug (20) MUST be manually held up if unit is not supplied with lower piston spring (22).

b. Remove temporarily installed diaphragm

lock nut (7) and spacers of previous Step E.5.c. this section.

c. Place new o-ring middle stem seal (14.2)

into groove of piston-guide bearing (13) upper surface.

d. Position lower diaphragm pusher plate

(10) over upper end of plug (20) with tongue and groove “groove” on up per side.

e. Place new o-ring upper stem seal (14.1)

over upper end of valve plug (20).

f. Place diaphragm(s) (9) over end of valve

plug (20). NOTE: For multiple di a phragms

(9) that include TFE material, the TFE should be on wetted side; for 3-ply TFE elastomer diaphragm (9), stackup is TFEHK-TFE, beginning with lower wetted diaphragm (9) ﬁ rst.

g. Place upper diaphragm pressure plate (8)

over upper end of plug (20) with tongue and groove “ridge” on lower side.

h. Place lubricant on valve plug (20) thread ed

end. Engage diaphragm lock nut (7) with upper end of valve stem (20) as far as possible manually.

i. Place a wrench on diaphragm lock nut (7)

and a torque wrench on the upper end of valve plug (20). Hold torque wrench sta tion ary and rotate diaphragm lock nut (7) to the following torque values:

Body Size

in (DN)

1/2" - 1" (15 - 25)

1 1/4" - 2" (32 - 50)

2 1/2" - 4" (65 - 100)

Torque Value

Ft-lbs (N-m)

60 - 70 (81 - 95)

120 - 130 (163 - 176)

180 - 200 (244 - 271)

DO NOT allow valve plug (20) to rotate against seat ring (21) during tightening.

j. This completes ITA reassembly.

8. Metal Diaphragm Designs: a. Install new diaphragm gasket (37) onto

body (23) diaphragm ﬂ ange.

b. Position diaphragm(s) (9) onto body's (23)

diaphragm ﬂ ange with bolt holes aligned.

c. Position upper diaphragm pressure plate

(8) onto center top of diaphragm(s) (9) with rounded side of plate (8) on bottom next to diaphragm (9).

9. Aligning matchmarks and bolt holes, place cover dome (25) onto body (23).

10. Reinstall all ﬂ ange bolts (11) and nuts (12) with nameplate (99) located under one bolt head. Hand-tighten nuts (12).

NOTE: If a 3-ply diaphragm is being used,

it is important that the diaphragm (9) is “pre formed” – pulled together to remove as much entrapped air as possible and allow formation of a diaphragm (9) convolution. Starting with

the body bolts and nuts (11,12) hand tight ened, “preforming” can be accomplished by any one of the following techniques:

a. Apply 30 psig (2.1 Barg) pressure to the

valve outlet. OR

Block the valve outlet and apply 30 psig

(2.1 Barg) under the di a phragm through the 1/4" (DN8) NPT (plugged) external pres sure sens ing connection on the valve di a phragm ﬂ ange.

b. Leave pressure on through tightening

of bolt ing (11,12).

11. Evenly tighten the body bolting (11,12) in an alternating cross pattern in one revolution increments to the following torque values:

Body Size

in (Dn)

1/2" - 2" (15 - 50) 30 - 35 (41 - 47)

2 1/2" - 4" (65 - 100) 45 - 50 (61 - 69)

Torque Value

Ft-lbs (N-m)

If supplied, remove pressure of previous Step 10.

G. Units with Supported Diaphragm Designs:

1. A supported diaphragm (9) construction is designated as Opt-81 High Outlet Pressure. Both upwards and downwards directions are protected against pressure reversal; i.e. pres sure on one side of diaphragm (9) with no pressure on other side of diaphragm (9).

2. Body Sizes 2" (DN50) and Smaller; Com po si tion Diaphragm. (See Figure 5.)

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Page 11

a. Body (23) is specially machined with a

shelf to capture a lower diaphragm sup port ring (35).

b. Cover dome (25) is specially machined to

provide a surface for the upper di a phragm (9) support. Lower diaphragm support ring (35) is captured by its location. Upon removal of cover dome (25) and di a phragm (9), the lower diaphragm support ring (35) can be lifted upwards and out of the body (23) cavity.

c. Reinstallation is a reversal of Step b.

above.

DO NOT HYDROSTATICALLY TEST WITH-

OUT COVER DOME PRESSURIZED. NOT AD HER ING WILL DO PHYSICAL DAMAGE TO INTERNALS THAT COULD REN DER THE UNIT IN OP ER A BLE.

2. Inboard Leakage Test. a. Release all loading pressure in cover

dome.

b. Pressurize inlet to 30 psig (2.1 Barg) with

air, GN

c. Tube outlet to a beaker of water to ob serve

number of escaping gas bubbles.

Inboard leakage path may be via plug/seat or dynamic side seal.

3. Pressure Containment Test. a. Pressurize inlet to 200 psig (13.8 Barg)

and outlet and cover dome to 150 psig (10.3 Barg) with air or GN

b. Spray liquid lead detector and check all

ex ter nal leak points; i.e. plugged con nec tions, di a phragm ﬂ ange and di a phragm bolting.

Figure 5: Opt-81 — Composition Diaphragm

Con struc tion, 2" (DN50) and Smaller

H. Converting Internal/External Sensing:

1. Disassemble the regulator and remove the diaphragm(s) (9) according to Steps 1-12 in Part B – Main Regulator Disassembly.

2. To convert from internal to external sensing, remove the drilled pipe plug (32) and install a solid pipe plug. Reverse this step for converting from external to internal sensing.

3. Reassemble the regulator according to Part F – Main Regulator Reassembly.

I. Pressure Testing:

1. If a hydrostatic pressure test is performed, pressure must be applied to all three of cover dome (25), inlet and outlet of body at the same level.

4. Excessive leakage will require disassembly, examination of sealing elements, correction of problem, reassembly and retesting.

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Figure 6: Location of Auxiliary Ports

Page 12

VIII. PRESSURE LOADING

SECTION VIII

1. Loading pressure can be supplied using various schemes. Please reference LOADING SYSTEMS on web-site for the schematics of these various schemes, including:

• pressure unloading using BPV

• pressure loading using PRV

• pressure loading using pilot

• pressure loading using I/P transducer

LOADING PRESSURE FOR MODEL DA4 APPLIED PRESSURES

2. The Model DA4 exhibits a deviation in outlet controlled pressure when the inlet pressure var ies; this “effect” is identiﬁ ed as ISR – Inverse Sympathetic Ratio. Its relative pressure effect can be calculated from the following equation.

ISR FACTOR

BODY SIZE

in (DN)

1/2" - 1" (15 - 25) 3.0

1 1/4" - 1 1/2" (32 - 40) 4.0

2" (50) 2.0

2 1/2" - 4" (65 - 100) 5.4

PISTON SPRING

LOWER PISTON SPRING RANGE

psig (Barg)

none (none) 0 (0) 0 (0)

2 - 5 (.14 - .34) 3 (.21) 2 (.14)

1 - 2 (.07 - .14) 1 (.07) 1 (.07)

4 - 10 (.28 - 6.9) 6 (.41) 4 (.28)

∆P Piston

Spring

psig (Barg)

ISR – %

LVPS

psig

(Barg)

SIZE / ORIENTATION – S/O Factor

Body Size

in (DN)

1/2" - 1" (15 - 25) 1 -1

1 1/4" - 1 1/2" (32 - 40) 2 -2

2" (50) 2.5 -2.5

2 1/2" - 3" (65 - 80) 3 -3

4" (100)

= ISR Effect +

LOAD

Compression Effect Spring Preload Orientation Effect

= P2 + [ISR x (P1 – P2)] +

Load

Lower Piston Spring + Lower Piston Spring + Body Size

Req'd

x ∆PPiston Spr. + LVPS + S/O

Max

Factor

Cover Dome

on Top

Figure 8: Loading Pres sure Formula

Orientation

Cover Dome

on Bottom

4-4

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Page 13

SECTION IX

IX. TROUBLE SHOOTING GUIDE

When trouble shooting this regulator there are many possibilities as to what may be causing problems. Many times, the regulator itself is not defective, but one or more of the accessories may be. Sometimes the pro cess may be causing difﬁ culties.

The key to efﬁ cient trouble shooting is information and communication. The customer should try to be as precise as possible in their explanation of the problem, as well as their understanding of the application and operating con di tions.

It is imperative the following information be provided by the customer:

• Fluid (with ﬂ uid properties) • Range of outlet pressure

• Range of ﬂ ow rate • Range of ﬂ uid temperature

• Range of inlet pressure • Range of ambient temperature

Pressure readings should be taken at every location where pressure plays a role - i.e., regulator inlet (as close as possible to inlet port), regulator outlet (as close as possible to outlet port), etc.

Following are some of the more common complaints along with possible causes and remedies.

1. Erratic regulation, instability or hunting.

Possible Causes Remedies

A. Sticking of internal parts. A. Remove internals, clean, and if necessary, replace.

B. Load changes are too quick for system.

C. Oversized regulator.

D. Too much variation in Inlet Pressure - P1. D. Consider use of a pilot for closer Outlet Pressure – P2

B. Convert to external sensing (if necessary) and install an oriﬁ ce or needle valve in external sensing line.

C. Check actual ﬂ ow conditions; resize regulator for min i mum and maxi- mum ﬂ ow; if necessary, replace with smaller regulator.

2. Erratic regulation, instability or hunting (liquid service).

Possible Causes Remedies

A. Air trapped under diaphragm. A. Install valve on external sensing port and bleed off air. (Install

regulator upside down to help prevent reoccurrence.

3. Downstream pressure will not reach desired setting.

Possible Causes Remedies

A. Supply pressure is down (conﬁ rm on pressure gauge.

B. Undersized regulator. B. Check actual ﬂ ow conditions; resize regulator for min i mum and maxi-

C. Pressure loading system pressure restricted. C1. Clean restriction or bleed oriﬁ ces.

D. Faulty loading pressure control device. D. Replace/repair loading pressure control device.

A. Increase supply pressure.

mum ﬂ ow; if necessary, replace with larger regulator.

C2. Clean ﬁ lter(s). C3. Clean loading pressure control device.

4. Diaphragm continually breaks (steam service regulators).

Possible Causes Remedies

A. Stem seals (14) which protect ﬂ uorocarbon elastomer in diaphragm assembly may have deteriorated.

B. Diaphragm nut (7) may not be torqued to correct value.

C. Diaphragm too stiff causing it to crack. C. Follow proper preforming and air evacuation techniques during

A. Replace with new stem seals (14).

B. Conﬁ rm torque value in accordance with Section VII, F-7-i.

diaphragm installation in accordance with Section VII, F-10.

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Page 14

5. Diaphragm continually breaks (all regulators).

Possible Causes Remedies

A. Differential pressure across diaphragm may have exceeded limits. (See Table 1 in DA4-TB)

A1. Be aware of limits as well as where the various pressures are acting. Install pressure safety equipment as necessary. A2. Consider if full diaphragm support, Opt-81, should be added.

6. Leakage at diaphragm ﬂ ange.

Possible Causes Remedies

A. Body bolts not torqued properly. A. Torque to proper value (see Section VII, F-11).

B. Pressures at diaphragm may be too high. B. Consult factory.

7. Leakage across seat.

Possible Causes Remedies

A. Contamination (debris) in regulator. A. Remove internals, clean, and if necessary, replace sealing and seat-

ing elements. *

B. Oversized regulator; valve plug operates directly next to seat.

* Seat leakage may be diagnosed when a failure of the dynamic side seal has occurred. Inspect both potential internal leak paths.

B. Check actual ﬂ ow conditions; resize regulator for minimum and maxi- mum ﬂ ow; if necessary, replace with smaller regulator.

SECTION X

X. ORDERING INFORMATION NEW REPLACEMENT UNIT vs PARTS "KIT" FOR FIELD REPAIR

To obtain a quotation or place an order, please retrieve the Serial Number and Product Code that was stamped on the metal name plate and attached to the unit. This information can also be found on the Bill of Material ("BOM"). a parts list that was provided when unit was originally shipped. (Serial Number typically 6 digits). Product Code typical format as follows: (last digit is alpha character that reﬂ ects revision level for the product).

–

PARTS "KIT" for FIELD REPAIR:

Contact your local Cashco, Inc., Sales Rep re sen-

NEW REPLACEMENT UNIT:

ta tive with the Serial Number and Product code. Identify the parts and the quantity required to repair

Contact your local Cashco, Inc., Sales Rep re sen ta tive with the Serial Number and Product code.

the unit from the "BOM" sheet that was provided when unit was originally shipped.

With this information they can provide a quotation for a new unit including a complete description, price and availability.

NOTE: Those part numbers that have a quantity indicated

under "Spare Parts" in column "A” reﬂ ect minimum parts required for inspection and rebuild, - "Soft Goods Kit". Those in column “B” include minimum trim replacement parts needed plus those "Soft

CAUTION

Do not attempt to alter the original construction of any unit without assistance and approval from the factory. All purposed changes will require a new name plate with appropriate ratings and new product code to accommodate the recommended part(s) changes.

Goods" parts from column "A".

If the "BOM" is not available, refer to the crosssectional drawings included in this manual for part identiﬁ cation and selection.

A Local Sales Representative will provide quotation for appropriate Kit Number, Price and Availability.

NOTE: In addition to ordering repair parts, it is recommended that a special double-posted spanner wrench

ﬁ tting be ordered for use in the main te nance of the ITA. See table on page 15 for part number.

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Page 15

Model DA4

Composition Diaphragm

(without Wiper Seal)

Item No. Description 7 Diaphragm Lock Nut 8 Upper Diaphragm Pressure Plate 9** Diaphragm 10 Lower Diaphragm Pusher Plate 11 Flange Bolts 12 * Flange Bolt Nuts 13 Piston-Guide Bearing

14** Stem Seals

14.1 Upper Stem Seal

14.2 Middle Stem Seal

14.3 Lower Stem Seal 15** Cage Seal 18 Cage Cap Screws 19 Cage 20 Valve Plug

Double-Posted Spanner Wrench Fitting

Body Size Part Number

All A96-75-9-P0459-00

The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. We reserve the right to modify or improve the designs or speciﬁ cations of such product at any time without notice. Cashco, Inc. does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any Cashco, Inc. product remains solely with the purchaser.

Item No. Description

21** Seat Ring 22 Lower Piston Spring (if supplied) 23 Body 24 Lower Guide Bushing 25 Cover Dome 26 Tap Plug (Not Shown) 27** Dynamic Side Seal (See Figure 1) 32 Internal Sensing Plug – Solid

(External Sensing Only)

33 Internal Sensing Plug – Drilled

(Internal Sensing Only)

99 Nameplate

* Not required on 2" CS & SST Body Material. ** Recommended Repair Parts.

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Page 16

Model DA4

Metal Diaphragm

(with Type UC – U-Cup Dynamic Seal)

Item No. Description 8 Upper Diaphragm Pressure Plate 9** Diaphragm 11 Flange Bolts 12 * Flange Bolt Nuts 13 Piston-Guide Bearing 15** Cage Seal 17 Camber Adjusting Washer 18 Cage Cap Screws 19 Cage 20 Valve Plug 21** Seat Ring 22 Lower Piston Spring

Cashco, Inc. P.O. Box 6 Ellsworth, KS 67439-0006 PH (785) 472-4461 Fax. # (785) 472-3539 www.cashco.com email: [email protected]

Printed in U.S.A. DA4-IOM

Cashco GmbH Handwerkerstrasse 15 15366 Hoppegarten, Germany PH +49 3342 4243135 Fax. No. +49 3342 4243136 www.cashco.com Email: [email protected]

Item No. Description 23 Body 24 Lower Guide Bushing 25 Cover Dome 26 Tap Plug (Not Shown) 27** Dynamic Side Seal (See Figure 1) 32 Internal Sensing Plug – Solid (External Sensing Only) 33 Internal Sensing Plug – Drilled (Internal Sensing Only) 37** Diaphragm Gasket 99 Nameplate

* Not required on 2" CS & SST Body Material. ** Recommended Repair Parts

Cashco do Brasil, Ltda. Al.Venus, 340 Indaiatuba - Sao Paulo, Brazil PH +55 11 99677 7177 Fax. No. www.cashco.com Email: [email protected]