HIGH PERFORMANCE BUTTERFLY VALVES - MODEL SLHBF & SLHBFFS
Australian Pipeline Valve - Installation, Operation and Maintenance Manual
5
DURING OPERATION BEAR IN MIND THE FOLLOWING WARNINGS:
a- The graphoil packing and body gasket is very brittle: any twisting or bending shall be avoided.
b- The internal parts of valves (disc, stem, seat) shall be handled with care avoiding scratches or surface
damage.
c- All tools and equipment for handling and supporting the internal parts shall be coated with soft
materials.
d- Seats & seals usually include Viton, Buna & Teflon hence high temperatures will damage sealing
components.
e- Never part open or part close valve, valve must be fully open of fully closed or else seats will be
damaged.
f- Check to see if the valve is specified for isolation service only or for control valve use or both (typically
metal seated valves are suitable for control valve use). Also, familiarise yourself with the shut off class
of the valve as various levels of shut off classes can be specified.
For all operations make reference to position number on part list of the applicable drawing and overview
diagrams 4 to 9. Overview explosions shown in diagrams 4 to 9 are general drawings only, for more
accuracy refer to the as-built drawings supplied with the order.
1 . 0 O V E R V I E W
1.1 GENERAL NOTE
High performance butterfly valves have a Double eccentricity and can be used for automatic proportion
control or isolation. However, for control valve use, valves must be metal to metal seated and throttling
over 75% closed or under 25% open will still dramatically reduce seat & disc and valve body life, even
more so at higher pressures and if service is not clean. Also for throttling/control applications, a special
metal to metal seat design must be specified which is typically class IV or V shut off. However, normally
the triple eccentric SLHBFFS-T is specified for control valve use or class VI shut off isolation service is
required. A simple and unique valve design enables the user to assemble and disassemble easily.
Only model SLHBFFS is firesafe not SLHBF. SLHBFFS must have graphite stem packing
or it is not firesafe. Even in metal to metal seat design if only class IV shut off then
the valve is not firesafe design. The valve is only firesafe if API 607 is indicated on
the lable and the material certificate. For fugitive emission service special packing
systems must be specified.
1.2 TYPE
Valves are classified as Wafer Type, Lugged Type or Flanged. Their principal parts consist of body, disc,
seat and stem. Material of each part is determined by the application and working condition of the valve.
