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Valves are a very important part of the piping technology
and are mainly used for isolating, control and safety applications in the
fluid transfer field.
The N.G.D Valve series is a new and entirely
unique concept in the valve industry, which make possible the
automatic control and safety functions, for fluid transfer system, without
any pilots, instruments, controllers, power supply or computers. In simple
words it can be described as a simple
magic
as it offers high-tech applications without the associated conventional
high-tech technology.
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The
N.G.D Valve series is the right
product in the right time when
one considers the urgent need for simple automation of existing plants and
pipeline systems, in the world and especially in Africa. The N.G.D Valve
series provides a bargain deal for plant automation, without the
associated high-tech
equipment and without the required high-tech
skilled personnel, mostly
when the following benefits are considered:-
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Reduction in the number of plant operators.
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Minimization of the need for high-tech skilled
personnel.
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Reduction in the sophistication level of the plant
control.
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Prevention of damages to plant, pipeline &
equipment, due the human error or human negligence and as a result the
saving of repair and loss of production costs.
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Reduction in capital cost for new plants.
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The N.G.D & I.T valves are
a PISTON type valves, developed, designed and patented in South Africa.
The first model was developed
in 1988, known as the "ROMFLO PV" series and was a specialised
high-pressure (0 - 25 MPa) range of isolating, safety and control valves
primarily for the high-pressure water reticulation systems in the deep
gold mines in South Africa.
The second model was developed
in 1993, known as the "ROMFLO" series and was an adaptation of
the "ROMFLO PV" series to the American ANSI/ASME standards, but
it was still the same specialised high-pressure (0 - 25 MPa) range of
isolating, safety and control valves primarily for the high-pressure water
reticulation systems in the deep gold mines in South Africa.
The third model is the "N.G.D"
series, developed in 1997 and it is a general all-pressure (0 - 25 MPa)
range of isolating, safety and control valves for general applications.
The "I.T" series,
developed in 2000 and it is a general all-pressure (0 - 25 MPa) range of
safety and control valves for general applications.
The N.G.D valves are a well
known to the South African gold and platinum mining industries and are
approved to all of the major mining houses. |
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The
N.G.D & I.T valve series utilises a piston type closure part with a
suitable “Area-Ratio”, to
perform the required isolating, safety or control function. This type of
technology has many advantages of which the most important are listed
below:
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Provides a low-cost, simple and powerful
actuating method.
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Multi-turn or half-turn type valves do
not require the torque assistance of gearbox.
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The valve shuttle with the special “Area
- Ratio” design is the pilot for all of the self-powered safety and
control valves.
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Utilising the shuttle as well as a pilot
provides for a very powerful pilot, which makes the safety and control
valves less vulnerable to precipitation of the build-up of corrosion
products.
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All of the N.G.D & I.T safety and
control valves can be powered and there for activated by a combination of
transmitters, switches and controllers with the advantages of utilising
solenoid valve’s instead of actuators.
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All of the self-powered N.G.D & I.T
safety and control valves are not accessible to unauthorised tampering
with the valve’s pre-set parameters.
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The sealing arrangement of all N.G.D
& I.T valves is of the pressure-assisted type, inducing low magnitude
of parasite friction forces.
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A cost-effective valve range to all
applications, mostly due to its simplicity, and its natural integrated
actuating system.
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All of the N.G.D valves are maintainable
while in line.
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No other parts of the valve are inserted
into the valve body except for the valve shuttle, which serves as a
carrier to all of the seats and valve seat.
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Most of the N.G.D valve parts are
interchangeable between the various applications, irrespective of the
pressure rating.
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The required operating torque for hand-wheel operated and electrically
actuated valves is minimal, at all valve positions and under full
differential pressure conditions, to avoid operating problems or the
necessitating of torque assisting devices.
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The required driving thrust
for pneumatic, oil-hydraulic and water-hydraulic actuated valves is
minimal, at all valve positions and under full differential pressure
conditions, to avoid operating problem or the necessitating of high
operating pressures.
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The actuating power is derived directly from the high-pressure fluid in
the pipeline.
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The safety valve opens or closes automatically
when the pre-set conditions are reached (flow-rate, pressure, water
level, etc).
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The N.G.D & I.T safety valves are
designed to enable the simple and quick on-site
testing of the safety parameters.
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The N.G.D & I.T control valves are
designed to prevent hunting occurrence
at low flow conditions.
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The N.G.D & I.T valves control flow
or pressure by a single valve,
irrespective of the required control or reduction ratios.
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References
detailing users names, plants, applications, reference persons and
duration in service can be submitted upon request.
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The
N.G.D & I.T isolating, safety and control valves are designed to
withstand severe conditions of corrosion, precipitation, cavitation, high
content of solid in suspension in water, low or high pH values, etc.
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Special consideration is given to backup
arrangements, spare units and spare part holding for the purpose of
minimising product losses due to breakdown downtime.
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The
availability of technical backup support is an important part of the N.G.D valves logistics,
catering for breakdowns, modifications, planning and system design.
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The
N.G.D & I.T manuals cover all aspects of preventive maintenance, repair &
inspection procedures, recommended spare parts and material
specifications.
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The
N.G.D & I.T valve range of isolating, safety and control valves
provides a simple, efficient, reliable and low-maintenance solution for
fluid applications, such as: -
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Hand-wheel operated valves
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Electrically actuated valves
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Pneumatically actuated valves
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Oil-hydraulic actuated valves
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Water hydraulic actuated valves
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Pressure reducing valves
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Flow control valves
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Level control valves
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Pressure relief valves
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Excess flow safety shutdown valves
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Most of the company’s products are protected
by local and overseas patent rights, of which the most important are
listed below.
| Patent
Number |
Patent
Description |
| U.S.A Patent No: 5,141,028 |
Romflo Valve |
| R.S.A Patent No: 89/2677 |
U-Cone coupling |
| R.S.A Patent No: 96/3562 |
A pipe coupling (Thercom) |
| R.S.A Patent No: 96/3848 |
An automatic safety and control
piston valve |
| R.S.A Patent No: 97/1110 |
A valve seat |
| R.S.A Patent No: 99/2135 |
A safety and control piston valve |
| R.S.A Patent No: 2000/3415 |
A
method and apparatus for the prevention of shock in
liquid transport systems |
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