A tilting-disc check valve uses an eccentrically pivoted disc that opens with forward flow and returns toward its seat when flow reverses. This calculator displays normalized pivot geometry and ideal thin-disc projected area only.
Tilting Disc Check Valve Interactive Calculator
Set an illustrative disc diameter, pivot position measured from the lower edge, and displayed opening angle from closed. Results are geometric, not hydraulic or dynamic predictions.
Equation Used
- Pivot position is measured along the displayed disc diameter from its lower edge.
- Opening angle is measured from the schematic closed plane.
- The disc is treated as infinitely thin for projected-area geometry.
- The lower/upper result is a length ratio only.
- Pressure, flow, Cv, head loss, torque, gravity, transient closure, slam, cavitation, leakage, friction, wear and safe selection are omitted.
Eccentric Tilting-disc Geometry
Val-Matic describes a tilting-disc check valve with eccentrically located pivot pins. In its documented design the disc rotates 40 degrees from closed to fully open, and the eccentric geometry lets the disc-ring seating surface move away from the seat without rubbing contact.
The schematic shows the general eccentric-pivot topology. It is not a manufacturing drawing and does not reproduce the product's triple-offset seat geometry.
What This Calculator Does
The tool converts normalized pivot position into a height, center offset and lower-to-upper displayed length ratio. It also reports the ideal projected open fraction of an infinitely thin circular disc rotated from the closed plane.
These quantities do not establish hydraulic performance, closing response or suitability.
Displayed Section Geometry
e = hp - D/2
R = hp/(D-hp)
ideal projected open fraction = 100(1-cos theta)
R is a length ratio, not a force ratio. The projected-area relation is a zero-thickness geometric proxy only.
Worked Geometric Example
For D=600 mm, p=66.5% from the lower edge and theta=40 degrees, pivot height is 399 mm, offset above center is 99 mm, the displayed lower/upper length ratio is about 1.99, and ideal projected open fraction is about 23.4%.
Model Boundary
- Source basis: eccentric pivot pins, a tilting disc and design-specific opening/seat geometry.
- Calculated: normalized section dimensions, a length ratio and ideal thin-disc projected area.
- Not calculated: flow area, Cv, head loss, pressure, velocity, torque, gravity moment, transient closure, reverse flow, slam, surge, cavitation, leakage, seating contact, friction, wear, dashpot behavior, strength or safe selection.
Frequently Asked Questions
Is the lower/upper ratio a force bias?
No. It compares displayed lengths only.
Is projected open fraction the valve's flow area?
No. Real flow passes through three-dimensional passages around the disc, shaft, seat and body.
Does 40 degrees apply to every tilting-disc valve?
No. It is documented for the cited Val-Matic design; use the selected manufacturer's drawing.
Does the calculator predict head loss or Cv?
No.
Does it predict closing time or slam?
No.
Can it size or select a valve?
No.
References
- Val-Matic, Tilted Disc Check Valve Operation, Maintenance and Installation: eccentric pivot pins, 40-degree travel, seat-ring motion and stated application limits.
- Val-Matic, Tilted Disc Check Valve brochure: approximately one-third/two-thirds offset-pivot description and design-specific seating geometry.
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