Differential Dry Pipe Valve Angled Clapper Design

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Solution Overview

Problem

Conventional differential dry pipe valves for fire protection systems are costly to manufacture due to complex machining requirements for the seat and clapper design, and they often have large dimensions and high pressure requirements, making them less efficient and more expensive to produce and install.

Innovation Solution

A differential dry pipe valve design featuring a gasket flange angled at 52.5 degrees, a polygonal gasket with varying spacing between air and water lips, and a clapper with a reduced travel angle, which allows for a more compact and efficient construction with a reset mechanism accessible for easy operation, reducing manufacturing costs and pressure requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional machining methods are used for the seat and clapper, then sealing precision is achieved, but manufacturing cost increases significantly

Engineering Contradiction:
Improvesealing surface precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention changes the geometric parameters of the clapper and seat by introducing an angled configuration (52.5 degrees) instead of traditional circular designs. This parameter change allows the sealing surfaces to be formed through simpler fabrication processes while maintaining the required sealing precision, thereby reducing manufacturing cost.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs asymmetric design in the clapper and seat geometry, departing from the conventional symmetric circular design. The angled clapper configuration creates asymmetric sealing surfaces that can be manufactured more economically while achieving the necessary sealing performance, thus resolving the contradiction between precision and manufacturing ease.

Inventive Principle:
Principle #4Asymmetry

2Ease of manufacture

If a standard circular clapper and seat design is used, then manufacturing is conventional, but the valve dimensions are large and pressure requirements are high

Engineering Contradiction:
Improveconventional manufacturingVSAvoidvalve dimensions
Core Design Contradiction:
Ease of manufactureVSLength of stationary object

Solution Approach 1:

By changing the geometric parameters from circular to angled configuration (52.5 degrees), the invention achieves more compact valve dimensions. The angled design allows for optimized force distribution, enabling the valve to function effectively at lower pressures and smaller sizes while remaining manufacturable using conventional techniques.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the clapper travels through a large angle to open, then the valve can be reset reliably, but the opening time increases

Engineering Contradiction:
Improvereset reliabilityVSAvoidopening time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention optimizes the dynamic characteristics of the clapper by configuring it at a specific angle (52.5 degrees). This angular configuration enables the clapper to achieve reliable resetting through controlled movement while reducing the travel angle required for opening, thereby decreasing opening time without sacrificing reset reliability.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design results in a more compact, efficient, and cost-effective valve with reduced pressure loss and faster opening times, allowing for installation in smaller spaces and lower supply pressure operations, while maintaining a differential pressure ratio of at least 5:1.

Implementation Method 1

a gasket seal (514) affixed to the valve body (108) rather than to the clapper (516)... The gasket seal (514) has an air lip (804) and a water lip (802)... wherein the gasket seal (514) is constructed to seal against the clapper (516)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a reset mechanism (114) comprised of a coil spring (120) and a reset rod (118)... the reset mechanism (114) is accessible from an outer surface of the valve body (108)

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

A differential pressure ratio between the air chamber (504) and the water chamber (502) is sufficient to maintain the clapper (516) in the closed position... a pressure differential is defined as the ratio of the air pressure to the water pressure that just allows the clapper to prevent the flow of water

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP2556858B1Differential dry pipe valve
Publication Date: 2019.07.31 RELIABLE AUTOMATIC SPRINKLER CO INC
  • EP2556858B1 patent drawingFigure 1
  • EP2556858B1 patent drawingFigure 2
  • EP2556858B1 patent drawingFigure 3

AI summary

A differential dry pipe valve is provided having a body including an inlet chamber having an inlet port, an exit chamber having an exit port, and a gasket flange positioned between the inlet and exit chambers facing the exit port, the inlet and exit ports being substantially aligned. The valve also includes a gasket attached to the gasket flange and an openable cover hingedly attached to the body. The gasket has an inner water lip in fluid communication with the inlet chamber and an outer air lip surrounding the water lip. The spacing between the water lip and air lip varies. The air and water lips are coaxial. The cover is configured to be sealingly engaged with the seal when in a closed position and to be sealingly disengaged in an open position when the pressure in the exit chamber is lower than the pressure in the inlet chamber. When the cover is in the open position, a direction of a path between the inlet and exit ports is substantially unaltered.