Dry Sprinkler Assembly With Coaxial Tube for K17 Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dry sprinkler assemblies with k factors of 11.2 or greater, particularly k17, using 1 inch NPS pipe are heavy, costly, and difficult to install due to larger pipe sizes.
Innovation Solution
A dry sprinkler assembly design featuring a 1 inch NPS pipe element with a wall thickness less than 0.095 inches, incorporating a valve with movable closing members and a temperature-sensitive trigger to achieve discharge rates equal to or greater than k17, utilizing a coaxially positioned tube with openings and a biasing mechanism for fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If larger pipe sizes are used to achieve k17 discharge rates, then the discharge rate is improved, but the weight, cost, and installation difficulty increase
Solution Approach 1:
The patent changes the geometric parameters of the pipe element, specifically using a 1-inch NPS pipe with reduced wall thickness (less than 0.095 inches) and optimized length (6 to 18 inches). This parameter optimization allows the smaller pipe to achieve k17 discharge rates by maximizing the flow cross-section while minimizing resistance, thereby reducing weight without sacrificing productivity.
Solution Approach 2:
The patent introduces a coaxial tube within the pipe element, creating a nested dimensional structure. This inner tube (with outer diameter smaller than the pipe's inner diameter) provides additional flow pathways and structural support, effectively increasing the discharge capacity of the 1-inch pipe to match k17 requirements without enlarging the outer pipe dimensions, thus avoiding weight increase.
2Productivity
If larger pipe sizes are used to achieve k17 discharge rates, then the discharge rate is improved, but the cost increases
Solution Approach 1:
The patent optimizes the pipe parameters (1-inch NPS, wall thickness less than 0.095 inches, length 6-18 inches) to achieve k17 performance with standard, cost-effective materials. By carefully selecting these parameters, the design avoids the need for expensive custom-large-diameter pipes while meeting the discharge rate requirement through optimized flow dynamics and the coaxial tube configuration.
Solution Approach 2:
The coaxial tube structure adds functional complexity without requiring larger external dimensions. This nested design allows the 1-inch pipe to deliver k17 performance using standard, readily available materials and manufacturing processes, thereby controlling cost while achieving the required productivity.
3Productivity
If larger pipe sizes are used to achieve k17 discharge rates, then the discharge rate is improved, but the installation difficulty increases
Solution Approach 1:
The patent specifies a pipe length of 6 to 18 inches, which is significantly shorter than traditional dry sprinkler assemblies. This reduced length, combined with the 1-inch NPS standard size, makes the assembly much easier to handle, position, and install in various locations. The optimized parameters allow for simpler support requirements and easier integration into existing piping systems while achieving k17 discharge rates.
Solution Approach 2:
The coaxial tube within the pipe element provides structural rigidity and flow management without increasing the external dimensions. This nested structure allows the compact 1-inch assembly to maintain its integrity during installation and operation, facilitating easier handling and installation compared to larger, more cumbersome pipe configurations.
4Weight of moving object
If wall thickness is reduced to use 1 inch NPS pipe, then the weight and cost are reduced, but the structural strength may be compromised
Solution Approach 1:
The coaxial tube (with outer diameter smaller than the pipe's inner diameter) provides internal structural support to the thin-walled 1-inch pipe. This nested structure reinforces the pipe element, preventing collapse or deformation under pressure while allowing the use of reduced wall thickness (less than 0.095 inches), thereby achieving weight reduction without compromising structural strength.
Solution Approach 2:
The pipe element functions as a composite structure combining the outer 1-inch NPS pipe with the inner coaxial tube. This composite configuration creates a stronger, more rigid assembly than either component alone, enabling the use of thin-walled material while maintaining the structural integrity required for fire suppression system operation.
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 enables reliable and effective fire suppression with improved flow rates and reduced installation challenges, achieving discharge rates equal to or greater than k17 using 1 inch NPS pipe.
Implementation Method 1
A temperature sensitive trigger is engaged with the second closing member and maintains the second closing member in engagement with the bore until an ambient temperature exceeds a predetermined threshold. The trigger releases the second closing member from the engagement with the bore when the ambient temperature reaches or exceeds the predetermined threshold
Data Source
Figure 1
Figure 1A~2A
Figure 2
AI summary
A dry sprinkler assembly for fire suppression uses a tube within a pipe element to maintain a spring loaded valve in a closed position at the end of the pipe element connected to a piping network. The tube is held against the biasing force of the valve's spring by a plug acted on by the temperature sensitive trigger of the sprinkler mounted on the opposite end of the pipe element.