Jafar 4499 Manuale di funzionamento e manutenzione - Pagina 6
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Stampa la pagina2 DESIGN
2.1 FITTING DESIGN DESCRIPTION
Manufacture and acceptance.
Butterfly valves are manufactured and accepted in accordance with PN-EN12266-1:2003 and PN-
EN583. Butterfly valves are tried with water for the casing and closing tightness, as well as with air for gas
media. Other operating conditions, such as temperature or conducted media, should be determined with the
manufacturer. Flangeless butterfly valves have closing components in the form of two-armed flaps, which turn
around an axis perpendicular to the medium stream. Manufactured within the scope of DN 250-800, they have
eccentrically mounted closing components. The ones intended for the flange-to-flange installation are
characterised by their shortened design. They can be mounted in horizontal or vertical pipelines. They are
manufactured with levers; the basic unit is the version presented in fig. 3
The butterfly valve consists of a body (item 1), a closing component (item 2) sturdily mounted on a shaft (item 4)
by use of cylindrical pins and a flexible ring (item 5). The butterfly valve shaft is mounted on rotary bearings in
bearing shells. For the purpose of ensuring tightness of the body at the point where the shaft moves through the
bearing shells, sealing rings were applied. At the edge of the body is a lathed socket of a sealing ring (item 5).
The sealing ring (item 5) is pressed with a cap (item 4), which has 2 bumpers as a reduction of the closing
component (item 2) position. The sealing ring consists of a metal insert encased in elastomer.
2.2 MATERIALS
Below, we present important components of the butterfly valve unit with the identification of the material
and standard.
NOTE:
The period of normal operation is limited by the ageing of the elastomer used for sealing the shaft and closing
component. This period lasts for:
- 4 years for the NBR mixture,
- 5 years for EPDM,
- 10 years for FKM,
Within this period the properly operated butterfly valve should be durable in the case of water and other
non-aggressive media at the working temperature ≤ 70°C.
No.
Part
Ductile cast iron
1
Body
EN-GJS-400-15
PN-EN 1563:2012
Ductile cast iron
2
Flap
EN-GJS-400-15
PN-EN 1563:2012
Ductile cast iron
3
Cap
EN-GJS-400-15
PN-EN 1563:2012
Steel: 1.4021
4
Shaft
PN-EN 10088-1: 2014
Rubber: NBR, EPDM, FKM
5
O-ring seal
PN-ISO 1629: 2005
OPERATION AND MAINTENANCE MANUAL
Material
01-2016
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