Fabric Reinforcement Diaphragms

The Type WD - 01 is commonly referred to as the "Top Hat" diaphragms.It exhibits all of the benefits that are associated with rolling diaphragms.These diaphragms have the longest stroke-to-bore ratio, zero spring rate, no breakaway friction, constant effective pressure area, and long life. Some of the drawbacks to Type WD-01 diaphragms are additional assembly time required when inverting the top head corner radius during installation, and an inability to withstand reverse pressure.The flange of the type WD-01 diaphragm is designed to seal like a gasket between the two flat surfaces of the cylinder and bonnet.The outside edge and bolt holes can be cut into any configuration desired. An effective seal should be obtained by compressing the flange area 20-30% by thickness.To extend cycle life and reduce "four-cornering" of the diaphragm, a double taper design may be utilized (see Figure 1). This design reduces the diameter of the bottom end of the diaphragm which minimizes excess material in this area and relives circumferential compressive stress.


For more detail please see attached pdf:

Fabric Reinforcement Diaphragms : In this style, the piston and the flange are molded on the same plane. The benefit of this style is that the handwork of forming the convolution is eliminated,which greatly reduces the assembly time. This would be if importance in high volume applications. The drawbacks to this type of diaphragm are; a built-in spring rate, due to the molded-in convolution, which must be considered during the design stage, and a limited stroke-to-bore ratio. To improve this ratio, an offset pre convoluted diaphragm can be designed (see WD-01 Offset figure at bottom of page). In this shape, the piston head and flange are milded offset to each other, thereby putting all the additional stroke capabilities on one side of the convolution.This provides a longer stroking diaphragm which still maintains the assembly ease of a pre convoluted diaphragm.

This is referred as Dish-Shaped Diaphragms which has sidewall that slopes gradually from the cylinder to the piston. We have designed this range of diaphragms to be flexed in both directions to its full height. We made these diaphragms using premium quality raw materials and designed them as per the guidelines of international quality standards.

Fabric Reinforcement In Diaphragms: This type of diaphragm has a rectangular bead molded inside the cylinder wall. This design requires the smallest hardware diameter of any diaphragm type. This type of diaphragm has only half the stroke capability of other diaphragm styles of the same height. Because the clamping and sealing of this style diaphragm is against the inside wall of the cylinder, the stroke is restricted to the lower half of the diaphragm.

Type o - This type of diaphragm has no flange. An O-ring is molded to the bottom of the sidewall.Unlike the other types of diaphragms, the Type O is put into convolution by folding the sidewall back onto itself. The bead is then squeezed into a groove machined into the bonnet half of the hardware. This type enable the greatest reduction in hardware diameter, while keeping a full stroke potential.

Type OA - This diaphragm type is a second generation to the Type O. It fits into identical hardware. It differs from the Type O in that its sidewall attaches to the inside diameter of the O-ring and the fabric is on the outside, requiring the head corner radius to be inverted for installation. The Type OA tends to be easier to install, but basically the difference is personal preference.

Hardware Design :

Fabric Reinforced Diaphragm is similar in function to the Type WD-02 diaphragm, while the sealing and hardware designs are the same as the Type WD-08.

Dimensions and Tolerances :

Reinforcement Diaphragm is the same as the Type WD-08 in all respects expect flange mounting. The parts are molded with what equates to half of an O-ring on the flange rather than a large that surface.This O-Ring half its into a groove machined into the cylinder half of the hardware. Sealing is achieved by squeezing the bead into a properly sized groove (see table at bottom of page). The cylinder and bonnet can then be designed to make positive contact when assembled, eliminating the need for a closely controlled assembly torque. It also reduces the overall diameter of the diaphragm, reducing the hardware diameter.