Sprinkler Check Valve Spring Pre-compression Drainage

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Solution Overview

Problem

In irrigation systems, water in uphill sprinkler pipes drains downhill through lower sprinklers due to gravity, causing puddles and damaging lawns, and existing check valves require large, expensive springs to prevent this, which adds manufacturing costs.

Innovation Solution

A small, spring-loaded check valve is inserted into the sprinkler body, pre-compressed to open only above a certain pressure level, preventing downhill drainage without modifying the irrigation system, and can be selectively installed or manufactured into the sprinkler housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional check valve with large spring is used to prevent downhill drainage, then drainage prevention is effective, but manufacturing cost increases significantly

Engineering Contradiction:

Improvedrainage prevention effectivenessVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the spring pre-compression parameter from traditional low pre-compression to high pre-compression (5-15 pounds force). This parameter change allows a small spring to generate sufficient closing force to prevent downhill drainage, replacing the need for large, expensive springs in traditional check valves while maintaining effective drainage prevention.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a small, inexpensive spring that can be easily replaced if needed, rather than a large, expensive spring that is difficult to replace. The small spring achieves adequate performance through high pre-compression, making it a cost-effective solution that is easier and cheaper to manufacture and maintain.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Ease of manufacture

If a small pre-compressed spring is used in the check valve, then manufacturing cost is reduced, but valve opening pressure threshold increases

Engineering Contradiction:

Improvemanufacturing costVSAvoidvalve opening pressure threshold

Core Design Contradiction:

Ease of manufactureVSStress or pressure

Solution Approach 1:

The patent adjusts the spring pre-compression parameter to create a higher opening pressure threshold (5-15 psi). This parameter change ensures the valve remains closed during normal operation and only opens when sufficient pressure builds up, preventing backflow while maintaining adequate water pressure for sprinkler operation. The higher threshold is acceptable because it prevents the specific problem of downhill drainage without compromising sprinkler function.

Inventive Principle:

Principle #35Parameter changes

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

This solution effectively prevents downhill drainage at a lower cost than traditional methods, allowing for selective installation and reducing the need for expensive springs, while maintaining adequate water pressure for operation.

Implementation Method 1

a spring-loaded check valve insert which can be screwed or pressed into the thread inlet of an existing sprinkler body with the spring on the poppet valve pre-compression loaded to open only above a certain pressure level

Methodology Applied

Scientific EffectSpring force: Spring

Implementation Method 2

The check valve puts an extra pressure drop in water supply line... water pressure pushing against the valve member overcomes the spring bias

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

where the sprinklers in the system are positioned at different relative elevations, after the main valve that controls the supply of water to the system is turned off, the water in the uphill portion of the supply pipe near the uphill sprinklers will tend to be drawn downhill by gravity and drain through one or more downhill sprinklers

Methodology Applied

Scientific EffectGravity: Gravitation

Data Source

PatentUS9162244B2Sprinkler body insertable check valve to prevent downhill drainage

Publication Date: 2015.10.20 KAH JR CARL L C

AI summary

A check valve for a sprinkler in accordance with an embodiment of the present application includes a valve body adapted to be positioned at an inlet of the sprinkler, wherein the valve body includes a central opening through which water flows into the sprinkler, a rib extending downwardly from the valve body at a location beyond the margin of the central opening, a valve member configured to cooperate with the central opening to open and close the valve. The valve member includes a valve stem extending downwardly from the valve member, and positioned and configured to be movably supported in a guide ring formed at a lower end of the rib, wherein the valve stem is movable vertically to move the valve member to its open and closed positions. The check valve further include a resilient member biasing the valve stem such that the valve member remains in the closed position until water pressure pushing against the valve member overcomes the bias of the resilient member.