Metallurgy
Techniques -New
Mode and A Variety of "Metal-to-Metal"
Coupling Devices for Demountable Pipeline Connections
Introduction
The invention of the new "metal
to metal" coupling devices relates to demountable
connections of any pipelines and can be employed in
various industrial and consumer engineering applications.
The devices can also be applied in stop valves of whatever
design. For the said applications, particular significance
of the proposed mode and a variety of implementing devices
is determined by nearly unique combination of such features
as : dependable functioning under considerable alternating
loads no need of fixing flanges to pipelines with leak-proof
quality thus short-cutting crucial welding or soldering
operations simultaneous meeting of stringent requirements
of working under extreme conditions of high pressure,
deep vacuum, major temperature drops and in corrosive
media Principle: The proposed technique of the "metal
to metal" coupling devices is based upon a special
configuration of the sealing element that allows to
make good use of elasticity of the material, of which
this element is made, so that complete sealing can be
reached whereas possibility of plastic deformations
is essentially diminished, thus ensuring multiple, repeated
use of the devices. The sealing element is made of alloy
steel (as a rule, a corrosion-resistant steel). It is
installed in the pipeline between the pipe ends and
sealing takes place along the inner edges of the pipe
inlets. In the same pattern the sealing element can
be employed to fit valves with no adjustment of their
components needed. Based on the proposed mode a variety
of sealing devices have been developed to be used in
various pipeline connections and in valves. Pipeline
connection application Despite the simplicity of the
basic design version in some connection embodiments
it can be even further simplified with no detriment
to its technical advantages. Sealing devices for stop
valves On the basis of the proposed technology sealing
devices for stop valves have been developed making it
possible to easily substitute existing rubber seals,
improving leak-proof capability and increasing multifold
a number of open/close cycles without change. Manufacturing:
Despite a specific configuration of the proposed sealing
element its manufacturing does not present any problem
and can be ensured by using well established metal-processing
technologies. In contrast to other metal-o-metal connections
that are characteristic of stringent requirements with
regard to precision machining of their parts, the proposed
seal design allows to maintain dimensional tolerances
with + 0,03 mm limits. Remaining parts of pipeline joints
or valve units are of general standard. Because it is
relatively simple to manufacture the proposed devices,
the costs of their serial production is comparable with
that of similar products available in the market, including
rubber seals, and it is essentially lower as compared
to costs of the above mentioned special devices with
high precision requirements. Trials and Tests Since
1993 a number of various pipeline couplings and valve
units have been tested (including those in real operation
conditions). The results obtained reliably confirm technical,
operational and economic advantages provided by the
proposed technology.
Area of Application
Fuel and ecologically adverse fluid
pipelines Pharmacological production: considering the
possibility of using the technology for high temperature
sterilization of pipelines without dismantling them
Chemicals production Automotive and aerospace industries:
bearing in mind smaller linear dimensions and lower
weight of the proposed devices Valves and fittings for
general industrial use, high pressure, cryogenics, vacuum
and high-vacuum engineering
Advantages
Dependable tightness retained under
considerable temperature drops Capability to withstand
variable mechanical impacts on the pipeline ensured
by total relieving of the sealing device from loads
Possibility to refuse from generally required leak-pr
Contact for more information:
Asian and Pacific Centre for Transfer
of Technology
APCTT Building
C-2 Qutab Institutional Area
P.O.Box - 4575
New Delhi - 110 016
India
