A
fabric reinforced diaphragm limits the stroke and provides a
frictionless seal. These diaphragms generally cost less, have more
tolerance range, and do not require hardened super finishes or
lubrication. The function of a diaphragm is the most important factor
in its design and manufacture. Simple diaphragms move from one
position to another, such as pressure switches and solenoid valves.
Diaphragms can be used as shock absorbers as in a dash pot or as
dampening devices in pulsating systems. Diaphragms can also be used
as barriers between fluids and gases, such as in a pressure drop on
the fluid side.
Diaphragms
are also used in pumps, such as automobile fuel pumps, hand pumps,
and diaphragm air compressors. In these cases an outside mechanical
force is actuating the diaphragm. This functions to displace a volume
of media. In the case of a pump the diaphragm creates a low pressure
area causing the fluid or gas to move into this area. In all the
above cases the function of the diaphragm will generally be the
determining factor when considering the type of construction, the
material composition, fabric design – weave or knit, and the type
of polymer.
A
fabric reinforced diaphragm is a unique product, incorporating both a
seal and reinforcement in one single structure. Plastic or metal
shrinkage techniques do not apply directly to the manufacture of a
fabric reinforced diaphragm. If this point is considered throughout
the product design process, a better understanding of the diaphragm’s
role and its capabilities within the hardware will be achieved. A
fabric reinforced diaphragm utilizes a layer of an engineered fabric
material as part of the diaphragm construction. This layer of fabric
give tremendous design flexibility. A very thin walled diaphragm can
withstand high pressures while remaining very flexible and responsive
to minor pressure variations.
Fabrics
made of polyester, nylon and silk are commonly used for most
applications, especially used for those applications exposed to high
temperature and for those applications that require extremely high
strength. It is important to note that fabric
reinforced diaphragms which are designed with round or circular
convolutions are neither round nor circular in the finished product.
Given that a fabric reinforced diaphragm is produced from a woven or
knit fabric with elastomer coating on one or both sides, there is an
intricate interplay of shrinkages and stresses between the fabric and
elastomer when a reinforced diaphragm is molded. The elastomer tends
to have a uniform shrinkage, while the fabric does not. The fabric is
an anisotropic material, it stretches more on the bias of the weave
and shrinks more in the direction of the weave. Additionally, the
fabric may impart a residual stress that may affect a reinforced
diaphragm’s dimensional stability.
Fabric
reinforced diaphragms have a distinct advantage over homogeneous
diaphragms. Supported diaphragms have less tendency to stretch under
conditions like pressure. Most importantly, fabric substrate takes
all of the stress from the rubber leaving the rubber to work in the
least stress conditions.
Darcoid
Nor-Cal Seal has extremely well qualified group of teams like
technical, engineering and development teams to understand and solve
problems of the clients with apt skills. Darcoid
Nor-Cal Seal is a privately owned company located in Oakland,
California. The
unique needs of your machinery are identified and every minute point
of necessity is taken into consideration in order to render the best
services for a safe and hassle free functioning of the machinery. The
company is an ISO 9001:2008 certified company provides the best
accessories for your machinery so as to help you enhance industrial
performance efficiency and make necessary changes to increase
standards and your machinery's productivity quotient. The
endeavor has
a vast experience in the industry and offer the design engineering
capabilities to deliver the exact solution for your applications in
regard to all kinds of sealing solutions.
