Cla-val 90-48/690-48 Quick Manual Manuel d'utilisateur télécharger pdf

SYMPTOM PROBABLE CAUSE REMEDY

Main valve No pressure at valve inlet Check inlet pressure

fails to open

Main valve diaphragm assembly Disassemble, clean and polish

inoperative stem, replace detective parts

Pilot Valve (CRD) not opening:

1. No spring compression 1. Tighten adjusting screw

2. Damaged spring 2. Disassemble and replace

3.Spring guide not in place 3. Assemble properly

4. Yoke dragging on inlet nozzle 4. Assemble properly

Flow Control (CV) disc inoperative. Disassemble, clean and polish

corrosion or excessive scale stem. Replace worn parts

buildup on stem

Main valve Foreign matter between disc and Disassemble main valve, remove

fails to close seat or worn disc. Scale on stem matter, clean parts and replace

or diaphragm ruptured defective parts

Flow Clean Strainer plugged Remove and clean or replace

CK2 (isolation valves) closed Open isolation valves

Pilot Valve (CRD) remains open:

1.Spring compressed solid 1. Back off adjusting screw

2.Mechanical obstruction 2. Disassemble and remove

obstruction

3.Worn disc 3. Disassemble remove and

replace disc retainer assembly

4.Yoke dragging on inlet nozzle 4. Assemble properly

diaphragm nut

5.Diaphragm damaged or loose 5. Disassemble. replace

diaphragm nut. Leakage from diaphragm and/or tighten nut

vent hole in cover

Fails to Air in main valve cover and/or Loosen top cover plug and

regulate tubing fittings and bleed air

Pilot Valve (CRD) yoke dragging Assemble properly

on inlet nozzle

Pilot Valve (CRD) spring not Check outlet pressure

in correct range to control requirements and compare

existing spring with Spring Chart

The Cla-val Model 90-48

Pressure Reducing Valve with Low Flow By-Pass

automatically reduces a higher inlet pressure to a steady lower downstream

pressure regardless of changing flow rate. The pressure reducing valve is

hydraulically operated and controlled by a CRD pilot control, which senses

pressure at the main valve outlet. An increase in outlet pressure forces the

CRD pilot control to close and a decrease in outlet pressure opens the control.

This causes the main valve cover pressure to vary, modulating the main valve

and thereby maintaining constant outlet pressure.

The control system is very

sensitive to slight pressure changes and immediately controls the main

valve to maintain the desired downstream pressure. Pressure setting

adjustment is made with a single adjusting screw

INSTALLATION

1. Allow sufficient room around the valve assembly to make adjustments

and for servicing.

2. lt is recommended that gate or line block valves be installed on both

ends of the 90-48/690-48 valve assembly to facilitate isolating the valve for

maintenance. Minimum one pipe diameter apart.

NOTE: BEFORE THE VALVE IS INSTALLED, PIPE LINES SHOULD BE

FLUSHED OF ALL CHIPS, SCALE, AND FOREIGN MATTER.

3. Place the valve assembly in the line with flow through the valve in the

direction indicated on the inlet plate or by flow arrows. Check all fittings

and hardware for proper makeup and that no apparent damage is evident.

Be sure main valve cover nuts/bolts are tight. Pressure in some applications

can be very high so be thorough in checking and inspecting for proper

installation and makeup.

4.Cla-Val Valves operate with maximum efficiency when mounted in hor-

izontal piping with the cover UP: however, other positions are acceptable.

Due to size and weight of cover and internal components of six inch and

larger valves, installation with the cover up is advisable. This makes period-

ic inspection of internal parts readily accessible.

Caution must be taken in the installation of this valve to insure that

galvanic and/or electrolytic action does not take place. The proper use

of dielectric fittings and gaskets are required in all systems using dis-

similar metals.

OPERATION AND START-UP

1. Prior to pressurizing the valve assembly make sure the necessary

gauges to measure pressure in the system are installed as required by the

system engineer. A Cla-Val X101 Valve Position Indicator may be installed

in the center cover port to provide a visual indication of the valve movement

during startup.

CAUTION: During start-up and test procedures a large volume of water

may be discharged downstream. Check that the downstream venting is

adequate to prevent damage to personnel and equipment. All adjustments

in pressure should be made slowly while under flowing conditions.

If the main valve closes too fast it may cause surging in upstream piping.

If isolation valves (B) are installed in pilot system open these

valves (see schematic).

3. Optional Cla-Val CV Flow Controls (C or S) provide adjustable regula-

tion of flow in and out of the main valve chamber to minimize pulsations

that sometime occur at very low flow rates. If CV Controls are installed,

loosen jam nut and turn adjustment screw counterclockwise from closed

position 3.5 turns for an initial setting.

4. Open the upstream gate or block valve just slightly to allow the main

valve assembly and pilot system to fill with liquid. Downstream gate or

block valve must be closed.

5. Carefully loosen tube fittings at highest points and bleed air from pilot

control system. Carefully loosen the plug at top of main valve cover to

bleed air from cover. If an indicator is installed, carefully loosen the air

bleed valve at top of indicator. Tighten tube fittings.

6. Open the upstream gate or block valve fully.

7. Slowly open the downstream gate or block valve. Flow should occur

and pressure should remain constant.

8. Adjust the Pilot Controls to desired pressure. To change pressure setting,

turn the adjusting screw clockwise to increase pressure, counterclock-

wise to decrease pressure. There must be liquid flowing through the valve

during pressure adjustments. When the desired setting has been made,

tighten jam nut and replace CRD cover. Low flow by-pass control (4) must

be set higher (minimum 5 psi) than main CRD (3).

9. To check the operation of the valve, open and close the downstream

gate valve. The downstream pressure should remain constant.

10. If opening and closing speed controls (C or S) are installed in the valve

pilot system, fine tune the opening and closing speed of the main valve

while performing step 9. Turn the CV adjustment screw clockwise on the

opening speed control to make the main valve open slower. Turn the

adjustment screw clockwise on the closing speed control to make the

main valve close slower. When adjustments have been completed

tighten jam nuts.

MAINTENANCE

1. Cla-Val Valves and Controls require no lubrication or packing and a

minimum of maintenance. However, a periodic inspection schedule should

be established. Minimum of once per year.

2. Repair and maintenance procedures of the Cla-Val Hytrol Main Valve

and pilot control components are included in a more detailed IOM manual.

It can be downloaded from our web site (www.cla-val.com) or obtained by

contacting a Cla-Val Regional Sales Office.

3. When ordering parts always refer to the catalog number and stock

number on the valve nameplate.

Pressure Reducing Valve with Low Flow By-Pass

90-48/690-48

MODEL

INSTALLATION / OPERATION / MAINTENANCE

1 2

Résumé du contenu

Page 1 - 90-48/690-48

SYMPTOM PROBABLE CAUSE REMEDYMain valve No pressure at valve inlet Check inlet pressurefails to openMain valve diaphragm assembly Disassemble, clean a

Page 2 - 90-48/690-48 SCHEMATIC CRD

CRD-40 Adjustment Range15 to 150 psiinletCover vent(3/8" NPT)CapAdjusting ScrewJam NutCoverSpringHex NutBelleville WasherDiaphragm WasherDiaphrag

Commentaires sur ces manuels

Pas de commentaire

Cla-val 90-48/690-48 Quick Manual Manuel d'utilisateur

Naviguer en ligne ou télécharger Manuel d'utilisateur pour Équipement Cla-val 90-48/690-48 Quick Manual. Cla-Val 90-48/690-48 Quick Manual User Manual Manuel d'utilisatio

Résumé du contenu

Commentaires sur ces manuels

Produits connexes et manuels pour Équipement Cla-val 90-48/690-48 Quick Manual