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OPERATIVE MANUAL 

MN-L20-A1

 

 

DC-18-10

 

 

 

 

 

MEC-RELA® 

- www.mecrela.it – [email protected]

 

a TERRANOVA® Srl brand

 - www.terranova-instruments.com - VAT IT07848810151 

Factory & Sales: Via Gramsci 1 – 26827 Terranova dei Passerini (LO) – Italy 
Head Office: Via Rosso Medardo 16 – 20159 Milano – Italy Ph: +39 0377 919119 – Fax: +39 0377 
855720 
 

Pa

g. 

16

/24

 

6.5

 

 

R

EPLACEMENT 

O

T

HE 

S

EAT

/P

LUG 

O

T

HE 

V

ALVE 

W

ITH 

Q

UICK 

C

HANGE 

S

EAT

 

By referring to Fig. 14 perform the following steps: 

 

Separate the actuator from the valve body as described in the previous paragraph. 

 

Loosen the nut (10) and fully unscrew the bolts (15). 

 

Separate the bonnet group (9) from the valve body (1). 

 

Remove the complete plug (3) from the bonnet (9). 

 

Remove the seat blocking cage (13) 

 

If required, remove and replace the seat (2). 

 

Insert in the bonnet (9) the new plug by paying attention to grease the stem with 
silicone oil. 

 

Always replace the body gasket (11) and the seat gasket (14) and carefully clean the 
supporting surfaces. 

 

Re-assemble everything by repeating the steps in the reverse order and pay specific 
attention to the realignment of stem, seat and plug. 

 

Gradually tighten the nuts (15) in criss-cross sequence, as indicated in the example 
in Fig. 2 paragraph 4.01 by applying the torques indicated in chapter 7.  

 



A

TTENTION

When the plug is being replaced it is also necessary to replace the packing gland (see next 
paragraphs). 

 

 

Fig. 14 - Valve with Quick Change seat

 

Содержание MEC-RELA L20-A1 Series

Страница 1: ...instruments com a TERRANOVA Srl brand www terranova instruments com VAT IT07848810151 Factory Sales Via Gramsci 1 26827 Terranova dei Passerini LO Italy Head Office Via Rosso Medardo 16 20159 Milano I...

Страница 2: ...6 Temperature 5 3 7 System 6 3 8 Pressurized Systems 6 3 9 Tools And Consumable Parts 6 3 10 Protection Clothes 6 3 11 Qualification Of The Operators In Charge Of The Works 6 3 12 Handling 7 3 13 Free...

Страница 3: ...ova dei Passerini LO Italy Head Office Via Rosso Medardo 16 20159 Milano Italy Ph 39 0377 919119 Fax 39 0377 855720 Pag 3 24 6 6 Replacement Of The Seat Plug Of The Balanced Valve 17 6 7 Replacement O...

Страница 4: ...to satisfy the needs of the industrial demand L20 valves are designed to control a broad variety of fluids like steam water most of the medium and gases One of the main features of this series is the...

Страница 5: ...ended to withstand any external stresses which can be induced by the systems in which they are inserted The installer must take account of these stresses and take the appropriate measures to prevent t...

Страница 6: ...block and vent and the blocking or the labelling of the closed valves Do not consider the system depressurized even if the pressure gauge indicates zero pressure The depressurization process should in...

Страница 7: ...rotect the product in freezing environments where temperatures are lower than the freezing point of the process fluid 3 14 OTHER RISKS During the operation the external surface of the product can be a...

Страница 8: ...pstream the valve will prevent dirt entering the valve To allow periodical maintenance of valves that are installed on continuously operating systems it is recommended to install two Isolating valves...

Страница 9: ...lly tightened in criss cross sequence as indicated in Fig 2 MANDATORY Prevent any excessive tightening Use the recommended tightening torques Prevent any pipe misalignment Choose the flange gaskets ac...

Страница 10: ...es 5 ACTUATOR CONNECTION 5 1 PNEUMATIC ACTUATOR CONNECTION The pneumatic actuator is provided with two 1 4 NPT connections one of which is closed by a filter Connect the control air pipe to the connec...

Страница 11: ...eed always refer to the above mentioned number INFORMATION During operation the valve is pressurized Before performing any maintenance operation or action on any pressure retaining part make sure that...

Страница 12: ...TERRANOVA Srl brand www terranova instruments com VAT IT07848810151 Factory Sales Via Gramsci 1 26827 Terranova dei Passerini LO Italy Head Office Via Rosso Medardo 16 20159 Milano Italy Ph 39 0377 9...

Страница 13: ...EMENT OF ON OFF PISTON DISC ON OFF VALVE Separate the actuator from the valve see section 6 3 In reference to the Fig 9 for reverse action actuators and the Fig 10 for direct action actuators proceed...

Страница 14: ...Pag 14 24 6 3 VALVE ACTUATOR SEPARATION By referring to Fig 11 for valves 1 2 4 or to Fig 12 for valves 6 8 perform the following steps Set the valve to the 50 stroke Fully unscrew the screws 1 and re...

Страница 15: ...te the bonnet group 9 from the valve body 1 Remove the complete plug 3 from the bonnet 9 If required unscrew and replace the seat 2 by using the specific wrenches Insert in the bonnet 9 the new plug b...

Страница 16: ...he bonnet group 9 from the valve body 1 Remove the complete plug 3 from the bonnet 9 Remove the seat blocking cage 13 If required remove and replace the seat 2 Insert in the bonnet 9 the new plug by p...

Страница 17: ...3 and the balancing piston 8 of the valve body 1 Remove any cage 5 Replace the sealing gasket of the balancing piston 8 by unscrewing the nut 16 If required unscrew and replace the seat 2 by using th...

Страница 18: ...lete plug 3 from the bonnet 9 Remove the pin 17 and remove the plug 3 If required unscrew the bellows block 19 and replace it by replacing also the gasket 18 If required unscrew and replace the seat 2...

Страница 19: ...vious paragraphs Fully unscrew the screw 1 Remove the upper packing gland 2 Remove the spring 3 Remove the lower packing gland 4 Replace the O ring 5 if present Carefully clean the housing chamber and...

Страница 20: ...ad Office Via Rosso Medardo 16 20159 Milano Italy Ph 39 0377 919119 Fax 39 0377 855720 Pag 20 24 7 TIGHTENING TORQUES VALVE DIAMETERS SEAT 1 Nm 10 BONNET NUTS 2 Nm 10 SCREWS 3 Nm 10 NUT 4 Nm 10 VD10 K...

Страница 21: ...erranova dei Passerini LO Italy Head Office Via Rosso Medardo 16 20159 Milano Italy Ph 39 0377 919119 Fax 39 0377 855720 Pag 21 24 VALVE DIAMETERS NUTS 9 Nm 10 NUT 6 Nm 10 RING NUT 7 Nm 10 SCREWS 5 Nm...

Страница 22: ...8810151 Factory Sales Via Gramsci 1 26827 Terranova dei Passerini LO Italy Head Office Via Rosso Medardo 16 20159 Milano Italy Ph 39 0377 919119 Fax 39 0377 855720 Pag 22 24 8 SIZES OF THE ACTUATOR CO...

Страница 23: ...d or erosion as they may significantly damage the pressurized parts by locally reducing the thickness and as a consequence the safety degree 10 AVAILABLE SPARE PARTS DESCRIPTION FIGURE POSITION Screwe...

Страница 24: ...instruments com a TERRANOVA Srl brand www terranova instruments com VAT IT07848810151 Factory Sales Via Gramsci 1 26827 Terranova dei Passerini LO Italy Head Office Via Rosso Medardo 16 20159 Milano I...

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