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Fujikura Diaphragm. IER Fujikura is a world leader in rubber molded diaphragms. Since 1901, we have used rubber and fabric composite technology for many application types. Over the last 40 years, we have developed and supplied high quality engineered diaphragms. Through our experiences and the use of FEA analysis, we also support the customer
to feel confident in the application of the engineered products.

Functions & Applications. Diaphragms are the membrane of the assembly and are used for various applications (see the functions and applications chart to the right). The primary applications are for the automotive controls, carburetor, water distribution, pump, gas, medical, and semi-conductor industries.
Air brake chamber, air cylinder, speaker cone, throttle, EGR, Waste Gate Valve
Fluid flow

Air pressure regulator, LPG Vaporizer, Fuel regulation Pressure Regulator, gas-governor city water pressure controlling valve
Fluid/ ON-OFF
Feed valve, Air control valve
Switch & Sensor
Oil pressure switch, Vacuum switch
Brake oil reserver tank
Air pump, Fuel pump, Water Level Switch

Rubber Compound For Environmental Conditions. For the media contacting the diaphragms such as ethanol/methanol gasoline, natural gas, chlorine water, we offer a wide range of specialty compounds. We support our customers in the design to meet functional, and in the material selection.

In the design of the fabric reinforced diaphragm, the type of fabric is decided by the pressure and temperature, where the fabric gives strength to the membrane. The first consideration is the environmental conditions of the
application – temperature range, contacting media, cycle rate and pressure and other considerations. Material used
for diaphragm is selectable from polyamide, polyester or aramid, in the thickness range between 0.075mm to 0.45mm. We will decide the optimal fabric based on the application requirements.

Flange Retention.
The outside diameter of the diaphragm is retained by different methods, and is usually a beaded or a square cross-section. This area of the diaphragm creates a seal, where the mating components apply the compression to the rubber cross-section. We optimize the design with the customer, based on the available area in the assembly and mating components.

Overmold / Insert Diaphragm.
We can mold the rubber or fabric-reinforced rubber to metal, plastic, or cork, to reduce the assembly cost. This also reduces the investment cost of assembly equipment.

Diaphragm Construction & Types.
Diaphragms can generally be classified as all rubber type and fabric reinforced type. For the extremely harsh condition, PTFE overmold type is also available. Please see the styles and construction types below.

Diaphragm Construction

All rubber (Homogenuous) type diaphragm
The rubber is constantly under tension as pressure is applied. The all rubber diaphragm is used when low pressure is expected. In general, these all rubber diaphragms offer lower manufacturing cost versus reinforced diaphragms. Homogeneous construction is possible using all types of elastomers.

One side coated/ Double sided fabric reinforced diapragm
A very thin fabric reinforced diaphragm can withstand high pressures while remaining flexible and responsive to minor pressure variations. The fabric reinforced diaphragms are oriented in the application where the rubber side is facing the high pressure, and fabric side is facing the low pressure. Double sided, fabric reinforced diaphragms are constructed where the fabric is inserted between two layers of rubber to withstand pressure in both directions.

Insert molded diapragm
By bonding metal or plastic inserts to diaphragms, some of the costly assembly operations can be reduced or eliminated. Additionally, rivet, screw or other fastening methods which might create leakpaths through the diaphragm would be eliminated with a bonded insert.

PTFE overmolded diaphragm
PTFE diaphragm is compatible with harsh environments without limiting the life and responsiveness of the diaphragm.

Diaphragm Types

Flat type diapragm
Flat type diaphragms are mainly used for pressure regulators and dumpers. The flat diaphragm has the limited stroke capability. We calendar different rubber materials, customized to meet the application requirements.

Top hat type diapragm
These diaphragms have the longest stroke capability, but are limited by the height.

Custom overmolded diapragm
We offer design support to our customer to overmold the rubber, or fabric-reinforced rubber, to the metal or plastic mating components to reduce the assembly cost.

Dish shaped type diapragm
These diaphragms have a sidewall that slopes gradually and are designed to be flexed in both directions.

Application Data Design Parameter Sheet. IER Fujikura is ready to assist you on your application design and to help select the best type of diaphragm. To make a satisfactory analysis of your specific application, we need to ask a few questions listed on a parameter sheet. It would also be helpful to receive a sketch or layout showing the proposed installation details. Please list any special requirements or environmental considerations if necessary. CLICK HERE
to see and print out the Diaphragm Parameter Sheet.