Product catalogue: Automatic control and heat ... - Polna S.A.

High temperature control valve.
The Z1A valve with a P-400 pneumatic actuator presented in the
photo is equipped with a SMART electropneumatic positioner and an air filter
reducer.
Thanks to the use of appropriate materials for the body and bonnet, the valve
can control the flow of a helium and nitrogen mixture with the temperature of
up to 600 o C.
Valve body and bonnet were entirely made from forged steel X10CrMoVNb9-1
(P91).
Body design with threaded holes for screws enables direct connection with
pipeline counterflanges.
Special design of internal parts made from stainless steel, which is hardened
with stellite, provides for proper flow regulation at extreme pressure drops.
Valve internal parts were designed in such a way to protect plug and stem
guiding elements along with sealings against wearing. They are covered them
from strikes of expanding steam by means of an internal cage of special design,
which is additionally sealed by a packing made from graphite of nuclear purity
(99,9998% of pure graphite).
Passage flangeless valve for working pressure of 530 bar.
All parts of the valve presented were made of 316L steel and counterflanges of X2CrNiMoN22-5-3 1.4462
(DUPLEX).
The valves were made for nominal pressure of PN630 as per BN-91 1771-20/40 standard, due to occurrence of
working pressure of 530 bar.
Sealing between valve body and counterflanges was designed based on BX 150 gaskets in accordance with API
6A Class 15000.
The valves feature guaranteed Class V of plug/seat shut-off at the full pressure drop of 530 bar, due to that fluid
flow was directed over the plug (FTC).
Pressure difference over and under the plug at shut-off causes additional thrust and unit seal.
In order to reduce required disposable force of actuator, special plug design (plug pressure balanced by inner plug
– so called pilot) was applied. Pilot was selected in such a way that force needed for its opening was 7 times lower
than that of main plug. After pilot opening, pressure above and under the main plug equalize and further opening
aiming at achieving a full passage does not require higher disposable force of actuator.
In order to prevent a wear and tear of internal parts caused by high velocity of fluid (liquid carbon dioxide) flow,
plugs, seats and guiding sleeves were made utilizing full stellited overlay with the hardness of 45 HRC. The valves
are equipped with pneumatic actuators, solenoid valves for control and open/closed position indicators.
The valves presented were designed and manufactured for Chemical Fertilizers Institute in Nitrogen Plant in
Pulawy.
28 Revision: SPECIAL VALVES/10/2014
Valid until the next revision.