ARI Armaturen STEVI 426 EN - Manual

Rev. 0040314001 0410 englisch
1.0 General information on operating
instructions ..................................................... 2
2.0 Notes on possible dangers............................ 2
2.1 Significance of symbols ..........................................2
2.2 Explanatory notes on safety information .................2
3.0 Storage and transport ................................... 2
4.0 Description...................................................... 3
4.1 Scope of applications ..............................................3
4.2 Operating principles ................................................3
4.3 Diagram ..................................................................4
4.3.1 Plug design ........................................................6
4.4 Technical data .........................................................6
4.5 Marking ...................................................................6
5.0 Installation....................................................... 7
5.1 General notes on installation...................................7
5.2 Requirements at the place of installation ................8
5.3 Installation instructions concerning actuators .........8
6.0 Putting the valve into operation.................... 9
7.0 Care and maintenance................................... 9
7.1 Replacement of stem sealings ............................... 9
7.1.1 EPDM-ring stem sealing design ........................ 9
7.1.2 Stuffing box packing design ............................. 10
7.1.3 Bellows seal design ..........................................11
7.2 Replacement of internal parts .............................. 12
7.2.1 Replacement of plug and stem ...................... 12
7.2.2 Replacement of seals of
pressure balanced plugs ................................ 12
7.2.3 Replacement of the seat ring........................... 13
7.3 Tightening torques................................................ 13
7.3.1 Tightening torques for nuts .............................. 13
7.3.2 Tightening torques for seat rings .................... 13
8.0 Troubleshooting ........................................... 13
9.0 Troubleshooting table ................................ 14
10.0 Dismantling the valve or the top part ...... 15
11.0 Warranty / Guarantee ................................. 15
12.0 EC declaration of conformity .................... 16
Contents
Operating and installation instructions
Straight through control valves - STEVI
®
425 / 426
Series 425 Series 426