Sprinkler Bore Geometry for K-Factor 30.8
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Solution Overview
Problem
Manufacturing a sprinkler system that achieves a nominal K-factor of 30.8 [gpm]/[psi]1/2 is challenging due to difficulties in achieving flow rates corresponding to target fluid pressures, particularly with existing sprinklers like VK514 and TYCO Model ESFR-34, which face issues with wall thickness and piping diameter requirements.
Innovation Solution
The sprinkler system includes a bore with specific geometries such as straight, stepped, or tapered portions, and inlet designs like radiused or chamfered portions, allowing for reduced friction losses and enabling a nominal K-factor of 30.8, which can connect with 1 inch national pipe tapered thread fittings, reducing the need for larger piping diameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If existing sprinkler designs (VK514, TYCO Model ESFR-34) are used, then fire suppression function is provided, but wall thickness and piping diameter requirements increase
Solution Approach 1:
The patent applies parameter changes by precisely controlling the bore geometry parameters (inner diameter, wall thickness, length) to achieve a specific K-factor of 30.8. By optimizing these dimensional parameters, the sprinkler achieves the target flow rate at lower pressures, eliminating the need for increased wall thickness or larger piping diameters that would be required with conventional designs.
2Ease of manufacture
If conventional sprinkler bore geometries are used, then manufacturing is simplified, but friction losses increase reducing flow rates at target pressures
Solution Approach 1:
The patent incorporates a radiused inlet portion in the bore geometry, applying curvature instead of sharp corners. This radiused design reduces turbulence and friction losses at the inlet, improving flow rates without complicating the manufacturing process. The curved transition allows smoother fluid entry into the bore, minimizing energy loss.
3Quantity of substance
If larger piping diameters are used, then flow rates increase, but system complexity and installation difficulty increase
Solution Approach 1:
The patent changes the sprinkler bore parameters (inner diameter, wall thickness, length ratio) to optimize the K-factor to 30.8. This parameter optimization allows the sprinkler to achieve high flow rates through standard-sized piping, eliminating the need for larger diameter pipes that would increase system complexity and installation difficulty.
4Quantity of substance
If higher system pressures are used, then flow rates increase, but pressure requirements exceed optimal operating conditions
Solution Approach 1:
The patent optimizes the bore geometry parameters (inner diameter, wall thickness, length) to achieve a K-factor of 30.8, which enables the sprinkler to deliver standard-compliant flow rates at lower pressures. This parameter optimization reduces the system pressure requirements from what would be needed with conventional sprinkler designs, operating effectively within the 5-200 psi range.
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 design achieves standard-compliant flow rates at lower pressures, reducing piping diameter requirements and system pressure needs, while maintaining effective fire suppression capabilities for various storage applications and ceiling heights.
Implementation Method 1
a thermal activation element between the seal and the deflector
Implementation Method 2
The bore can be shaped so that a nominal K-factor of the sprinkler is 30.8... reduced friction losses
Data Source
AI summary
A sprinkler includes a body defining a bore extending from an inlet to an outlet. At least one of an inner diameter and a wall thickness of the bore can be sized such that a K-factor of the sprinkler is within a threshold of 30.8, the K-factor defined in units of gallons per minute [gpm]/(pounds per square inch [psi])1/2.