Restated Project Scope

Problem Statement

Once the piping in a fire suppression system or the sprinkler system riser (water supply) has been disabled or broken in any part of the system, the entire system is rendered inoperable.  The purpose of a fire suppression system is to control the fire until the fire department arrives.  This gives occupants a greater chance of survival by allowing them additional time to escape from a building.  Currently, there are no bi-directional flow control valves on the market.  The valves that do exist only control the flow in one direction.  A bi-directional flow control valve has been designed and must now be manufactured.  The manufacturing process must ensure that the housing meets the performance specifications of the project.  These include a 1.5 inch NPT pipe housing and allowing initial threshold flow values of 60, 70, 80, 90, and 100 gallons per minute.  The valve must recognize when the pressure drop exceeds the minimum required to maintain flow.

Justification/Background

One of the lessons learned from the terrorist attack on the Pentagon on September 11, 2001, is that a fire suppression system can be taken out of operation with a single malicious act.  At present time, there is no flow control valve available on the market to prevent this from happening.  A bi-directional flow control valve has been designed for the client, the Air Force Research Laboratory (AFRL) at Tyndall Air Force Base (AFB).  This product will be able to be used in all types of occupancies where a fire suppression system is installed.  In particular, this product will help provide enhanced security for our nation’s high priority buildings by ensuring the fire suppression system in these buildings will not be able to be disabled maliciously.  In addition to using the bi-directional flow control valve, the fire suppression system will also be designed to use a two riser system to supply water.

Objective

Design and fabricate a bi-directional flow control valve that will close automatically, by sensing a pressure drop, if either side of the piping is broken.  The valve will sense a pressure drop when threshold water flow is exceeded in either direction.  The valve will not leak, but will incorporate a small leakage flow when closed in order for the valve to restart once the piping is repaired.  This leakage flow will be contained within the valve.  Common tools will be able to be used to install valve onto standard National Pipe Thread (NPT) piping.  A bi-directional valve system would be able to isolate a broken pipe.  This will stop the problem of water continuing to flow after a break, and more importantly, allow the system to still operate after a pipe is broken.  The valve should accept a 1.5 inch NPT pipe and allow initial threshold flow values of 60, 70, 80, 90, and 100 gallons per minute.
The fall semester was spent designing the bi-directional flow control valve and performing the necessary flow calculations.  The spring semester will utilize CFD modeling software to verify flow and successfully fabricate the prototype.  This includes manufacturing the parts, assembly of the valve, assembly of the testing apparatus, and testing the valve for successful operation.

Methodology

The project began with researching valves and related material to get as much background information on the subject as possible.  Once sufficient information was gathered, the group began designing a bi-directional flow control valve.  MathCad software was used to determine the pressure drop and flow actuation calculations.  Computational Fluid Dynamic (CFD) software will be used to analyze and model the valve operation to verify pressure drop and flow actuation.  Fabrication will begin in the spring semester keeping in mind all design specifications.  Once the valve has been fabricated, it will be tested ensure it meets all the criteria set forth by the client.  The Tallahassee Fire Training Center has agreed to allow team nine the use of their facilities in order to conduct the testing. 

Expected Results

The overall expectation of this project is a working prototype of a bi-directional flow control valve by March 2010.  The prototype will be able to allow for multiple internal components (springs and poppets) which will accept five different flow rates.  Using test piping with a fire hydrant, flow meter, and appropriate valves, the flow properties and the functionality of the set up will be demonstrated and tested.  Our results and trials will be fully displayed and explained verbally as well as visually.  Included in the final deliverable, among other things, will be test results, costs, trial, and final designs.

Constraints

AFRL at Tyndall AFB has provided extensive information on the desired functionality of the end product, along with the pledge to support this project in any way necessary.  The testing apparatus which includes, flow meters, pipes, and valves will be provided by AFRL and the Tyndall AFB Fire Department.  Constraints include, budget, fire hydrant availability for testing, CFD modeling software, and flow meter calculations.