Connecting and face-to-face dimensions:
Main and connecting dimensions are evident from the table.
During manipulation with ball valve the trunnion cannot be ejected from body.It is primary and secondary sealed by two independent rings. It can be tertiarysealed by injection of sealing paste. Secondary sealing ring can be replaced evenat full differential
Antistatic design of ball valves:
Antistatic design of ball valves provides conductive connection between the ball
and the body. Electrostatic charging of the ball is thus excluded.
There are different types of ball valves control: manual, electric, hydro-pneumatic,
electric-hydraulic, pneumatic. MSA supplies actuators of different
brands according to customerīs requirement, for example EXEECO,MASTERGEAR, ROTORK, AUMA
See the following tables.
Pressure tests of ball valves are done according to API SPEC 6D, API STD 598
or DIN 3230 standards. According to customerīs requirement it is possible to
perform the following tests
- shell and tightness test ( hydrostatic ),
- tightness ( by air ),
- seat tightness ( by air ).
Ball valves are intended for complete closing or
opening of working media flow. Working media:
sweet or sour natural gas, crude oil and its
products and non-aggressive water. The ball
valves are used in the following industrial fields:
gas manufacture, crude oil transport and
processing, petrochemistry, water supply.
Bodies of MSA ball valves are cast. They are
designed to fulfill strength requirements
according to corresponding standards with
minimum weight, but also to be stiff enough at
simultaneous action of external forces and
pressure. Ball valve bodies are designed to
transfer greater forces than pipelines to which
they are mounted.
Cast bodies are used in locations, where lower
weight and smaller dimensions are required -
buildings, compression stations.
The necessary thrust of a seat to a ball at low
pressure is provided by spiral springs. The
thrust is of a seat to a ball at higher pressure is
increased by pipeline pressure. Two seat types
seats with hard sealing ring - this type is used
mostly for liquid working media. DEVLON,
NYLON or PTFE is used as a primary sealing ring.
seats with soft sealing ring - this type is used
mostly for gaseous polluted working media.
NITRILE, MBR or HMBR is used as a
secondary sealing ring.
Both seat types are supplied in fire safe
Forces arising by applying pressure to the ball
are caught by self-lubricating PTFE bearings
with low friction coefficient. Thus the ball
valves have low torque and do not require any
Pressure reduction in a body:
Pressure in body cavity exceeding by about
150 PSI (N/mm2) pipeline pressure is
automatically relieved into pipeline.