Dry Sprinkler Inlet Structure for High K-Factor Flow

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Solution Overview

Problem

Existing dry sprinklers face challenges in achieving high K-factors, particularly greater than 14, due to internal components that inhibit fluid flow, and lack versatility in coupling arrangements, making them unsuitable for various installation types and sizes.

Innovation Solution

A dry sprinkler design with a dual connection arrangement featuring threaded and grooved couplings, an internal structural assembly, and a sealing mechanism that allows for various nominal K-factors and inlet sizes, ensuring consistent fluid flow and compatibility with different system configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a seal assembly is positioned at the inlet of a dry sprinkler to prevent water entry, then the sprinkler can be used in dry pipe systems, but the seal assembly occupies internal volume and creates resistance to water flow that prevents achieving high K-factors greater than 14

Engineering Contradiction:
Improveseal assembly functionalityVSAvoidfluid flow rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The sealing assembly is completely removed from the inlet body and relocated to the extension nipple, extracting the sealing function from the flow path. This allows the inlet body to have unobstructed internal volume and geometry optimized for high K-factor flow performance while the extension nipple provides sealing at its distal end where it connects to the sprinkler body.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sealing function is moved from the inlet body (first dimension) to the extension nipple (second dimension), allowing the inlet body to be designed purely for flow optimization while the extension nipple handles both connection and sealing functions in a different spatial location.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If internal components are arranged to position the closure assembly at the sealing surface, then the sprinkler seals properly in unactuated state, but little internal volume remains for the seal assembly or support members

Engineering Contradiction:
Improvesealing performanceVSAvoidinternal volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The sealing assembly is extracted from the inlet body and positioned in the extension nipple, creating sufficient internal volume in the inlet body for optimized flow geometry and K-factor performance while maintaining proper sealing function at the distal end of the extension nipple.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If a single inlet fitting design is used, then manufacturing is simplified, but the sprinkler cannot accommodate various coupling arrangements (threaded, grooved, dual) for different installation types

Engineering Contradiction:
Improveinlet fitting productionVSAvoidcoupling arrangement options
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The inlet fitting is designed with multiple coupling options integrated into a single component. The fitting can be configured with threaded couplings, grooved couplings, or dual arrangements, allowing a single inlet body design to serve multiple installation types and system configurations without requiring separate fittings for each application.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Productivity

If the seal assembly is rotated or altered in position to permit flow, then water can pass through the sprinkler, but greater force is required and resistance to flow remains that inhibits achieving high K-factors

Engineering Contradiction:
Improvefluid flow capacityVSAvoidforce required to move seal
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The sealing assembly is completely removed from the flow path in the inlet body and positioned in the extension nipple. When the sprinkler actuates, the closure assembly moves linearly within the extension nipple without requiring rotation or alteration of the sealing assembly's position, minimizing the force required and eliminating flow resistance that would prevent achieving high K-factors.

Inventive Principle:
Principle #2Taking out (Extraction)

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 achieves desired K-factors ranging from 16.8 to 33.6 GPM/PSI ½, supports multiple installation types, and maintains efficient fluid flow while minimizing weight and size for easy handling and installation.

Implementation Method 1

a mechanism that connects a thermally responsive component to the closure assembly

Methodology Applied
Scientific EffectThermal response: Thermal Expansion

Implementation Method 2

a spring assembly within the extension nipple that is engaged with the closure assembly and stores energy to move the closure assembly from an unactuated position to an actuated position

Methodology Applied
Scientific EffectSpring elasticity: Elasticity

Data Source

PatentEP3597273B1Dry sprinkler assemblies
Publication Date: 2025.11.26 TYCO FIRE PRODUCTS LP
  • EP3597273B1 patent drawingFigure 1A~1B
  • EP3597273B1 patent drawingFigure 1C~1D
  • EP3597273B1 patent drawingFigure 2~3

AI summary

A dry sprinkler for a fire protection system having a configuration with one or more coupling arrangements for connection to a fluid supply piping of the system. The dry sprinkler structure further includes an inner surface and inner assembly to provide a preferred discharge performance. The dry sprinkler provides for a flow rate from the outlet of the sprinkler in accordance with the start pressure at the inlet of the sprinkler and the rated discharge coefficient, K factor, ranging between 16.8 GPM/PSI½ and 33.6 GPM/PSI½.