Fire Pump Testing Requirements & Practices. Tom Jordan, FPE Facilities Engineering Cornell university

Fire Pump Testing Requirements & Practices Tom Jordan, FPE Facilities Engineering Cornell university

Who s in the Audience?

Presentation Outline Cornell and its systems Pressure and flow Fire pumps explained The Codes and fire pump testing Procedures and practices Precautions and lessons learned

PART 1 An Overview

My Background I m not in the fire service.but, my grandfather was for 23 years

My Background Bachelors in Mechanical Engineering

My Background 19 years at Cornell University

My Background First part of my career: designing building HVAC systems

My Background Which led to sprinkler system design

My Background And a Masters in Fire Protection Engineering

My Background Licensed in Mechanical and Fire Protection Engineering

Cornell University Over 1200 buildings between central campus & other locations in NY State Roughly 18M GSF

Cornell University Over 200 sprinkler systems on central campus Mix of dry-chemical, gaseous, and foam systems

Cornell University And of course, 39 Fire Pumps

Cornell University In-house IT&M (Inspection, Testing and Maintenance) program Performed by Environmental Health & Safety and Cornell Shops Periodic building FP Systems IT&M Weekly fire pump runs Annual fire pump testing

PART 2 Fundamentals of Pressure and Flow

Fundamentals Goals: Learn about various terms: Head Pressure Learn how to convert head to pressure and vice versa Learn about pressure as it relates to water Learn about the components of pressure Learn about flow and how pressure relates to flow Learn how to create and read a water supply plot

Fundamentals Most Important Goal:

Fundamentals Not this.

Fundamentals What is Hydraulic Head? 2,600 yrs. ago, Romans had gravity water systems.

Fundamentals What is Head? About 2,200 years ago, Archimedes invented the a screw to lift water.

Fundamentals What is Head?

Fundamentals What is Head? About 2,200 years ago, Archimedes invented the a screw to lift water.

Fundamentals What is Head? As the screw turns, water level rises The column of water grows Adds more weight Requires more force

Fundamentals What is Head? No concept of pressure at that time Needed a way to quantify how much force was required to lift water Developed the term feet of head Based on a the weight of a column of water So, what the hell does that mean???

Fundamentals What is Head? Plastic ice cubes 1 cubic inch Each weighs 0.036 pounds.

Pressure Fire Pump Testing Requirements & Practices What is Head? More cubes equals more weight Now, if we stack 12 cubes of water. 0.036 lb. x 12 cubes = 0.43 lb./ft. Foot of Head = The Weight of Water 1 Foot in Height Per Unit Area

Pressure Fire Pump Testing Requirements & Practices What is Head? 2-Feet = 0.86lb. 3-Feet = 1.29lb. 4-Feet = 1.72lb. 10-Feet = 4.3lb.

Pressure Fire Pump Testing Requirements & Practices What is Head? Now, what if we want to know how many cubes equals 1 lb. Stack cubes and weigh them Or, do some math = 28 cubes = approx. 2.31ft.

Fundamentals What is Pressure? Blaise Pascal clarified concept in 1643. Pressure (P) equals the Force (F) divided by Area (A) P = F/A P = Pounds/Square Inch (PSI)

Pressure Fire Pump Testing Requirements & Practices Another way to consider pressure.

Pressure Fire Pump Testing Requirements & Practices Pipe

Pressure Fire Pump Testing Requirements & Practices Example A 200 lb. person standing on the floor exerts how much pressure on the floor? Each foot carries half the force. Each foot = 50 sq. in.

Pressure Fire Pump Testing Requirements & Practices Solution P = F/A P = 100lb/50in 2 P = 2 lb./in 2 (PSI) P = 200lb/(50in 2 + 50in 2 ) P = 2 PSI

Pressure Fire Pump Testing Requirements & Practices What is Pressure? 1-ft of Head= 0.43 lb./ft. What is the pressure? If F = 0.43 lb. And A = 1 sq. in. Then F/A = 0.43/1 = 0.43 lb./sq. in. /ft. = 0.43 PSI/ft.

Pressure Fire Pump Testing Requirements & Practices What is Pressure? Same holds true for a cubic foot = 1728 oneinch cubes = 62.4 pounds of force per cubic foot. 62.4lb. / 144 cubes = 0.43lb./sq. in. (psi)

Pressure Fire Pump Testing Requirements & Practices Head and Pressure So, at this point we know for the 1 sq. in column of water: 1-ft. = 0.43lb./sq. in. 1-lb./sq. in. = 2.31ft. of Head

Pressure Fire Pump Testing Requirements & Practices Head and Pressure Relationship between these two numbers. Used to convert: Head to Pressure Pressure to Head

Pressure Fire Pump Testing Requirements & Practices Equations Cheat Sheet Pressure = Head 2.31 = PSI or Pressure = Head x 0.43 = PSI

Pressure Fire Pump Testing Requirements & Practices Equations Cheat Sheet Head = Pressure 0.43 = Ft. or Head = Pressure x 2.31 = Ft.

Pressure Fire Pump Testing Requirements & Practices Pressure in a piping system

Pressure Fire Pump Testing Requirements & Practices Three types of pressure: Static Pressure Residual Pressure Velocity Pressure Total Pressure is the sum of these three types: P T = Static P + Residual P + Velocity P

Pressure Fire Pump Testing Requirements & Practices Static Pressure Is pressure that is exerted on a surface when there is no movement or flow.

Pressure Fire Pump Testing Requirements & Practices Static Pressure

Pressure Fire Pump Testing Requirements & Practices Not Static Pressure

Pressure Fire Pump Testing Requirements & Practices Static Pressure of Water

Pressure Fire Pump Testing Requirements & Practices Static Pressure of Water P = Head x 0.433 = Pressure P = 140ft x 0.433psi/ft. = 60.6 psi P = Head / 2.31 = Pressure P = 140ft/2.31psi/ft = 60.6 psi

Pressure Fire Pump Testing Requirements & Practices Water Flow Test Summary

Pressure Fire Pump Testing Requirements & Practices

Pressure Fire Pump Testing Requirements & Practices Residual Pressure

Pressure Fire Pump Testing Requirements & Practices Residual Pressure Result of water discharge (flow) from an opening in a closed system.

Pressure Fire Pump Testing Requirements & Practices Residual Pressure When the opening gets bigger, flow increases, so the ability to contain the pressure decreases. 60 PSI 40 PSI

Pressure Fire Pump Testing Requirements & Practices Residual Pressure So, residual pressure is dependent on the flow rate leaving the closed system. It is also dependent on things like: The magnitude of the supply (or source) pressure And on the size of the piping distribution system:

Pressure Fire Pump Testing Requirements & Practices Residual Pressure Elevation also affects residual pressure!

Pressure Fire Pump Testing Requirements & Practices Residual Pressure Per the previous water tower example, with water now flowing in the building s sprinkler system, the pressure changes.

Pressure Fire Pump Testing Requirements & Practices Residual Pressure 800 GPM flow Assume water in tank is replaced at same rate, so level doesn t change Measured pressure drops to 40 PSI

Pressure Fire Pump Testing Requirements & Practices Residual Pressure Plotting the known static pressure and one flow rate & residual pressure will allow one to understand the residual pressure at any flow rate.

Pressure Fire Pump Testing Requirements & Practices Residual Pressure Any point on the line represents a flow and pressure relationship. With a known pressure, flow can be found. A given flow will reveal the pressure.

Pressure Fire Pump Testing Requirements & Practices Velocity Pressure Also known as Dynamic Pressure. Created by the flow of a liquid in a closed system (pipe). Insignificant, so ignored when flow testing fire pumps and other systems.

Flow Fire Pump Testing Requirements & Practices What is flow? Flow is the continuous movement of a liquid or gas in a stream.

Flow Fire Pump Testing Requirements & Practices What is flow? As a fluid flows in a pipe, friction is created.

Flow Fire Pump Testing Requirements & Practices What is flow? Higher friction equals greater resistance to flow of the liquid.

Flow Fire Pump Testing Requirements & Practices What is flow? System pressure is reduced as water travels through the piping system because of friction.

Flow Fire Pump Testing Requirements & Practices What is flow? Example of friction and pressure: McDonalds Straw vs. School Straw

Flow Fire Pump Testing Requirements & Practices What is flow? Flow is dependent on the total pressure loss in a piping system, which is a combination of: Elevation pressure loss (or gain) Friction-related pressure loss

Flow Fire Pump Testing Requirements & Practices What is flow? Elevation pressure loss

Flow Fire Pump Testing Requirements & Practices What is flow? Friction-related loss

Summary 1-Foot of Head = 0.43 lb. / sq. in. 2.31-Feet of Head = 1.0 lb. / sq. in 0.43 and 2.31 convert Feet of Head to PSI and vise versa Static Pressure = No flow and is dependent on elevation Residual Pressure = Lower pressure than static pressure

Summary Continued As elevation decreases, static pressure decreases As elevation increases, static pressure increases When piping length increases: Friction increase System residual pressure decreases Total pressure loss in a piping system is a combination of the elevation pressure loss and the friction-related pressure loss.

Questions??

PART 3 FIRE PUMPS

Fire Pumps Goals: To learn about types of fire pumps and major components To learn how fire pumps work To learn about fire pump curves To learn about cavitation To learn about Net Positive Suction Head

Cornell University What exactly is a fire pump? It s a mechanical device that increases water pressure and flow in a fire sprinkler or standpipe system.

Cornell University Fire pump

Cornell University Fire pump, but

Cornell University Why do we need a fire pump? Per FCNYS, section 508.1 (2010) or 507.1 (2015),Required Water Supply: An approved water supply capable of supplying the required fire flow for fire protection shall be provided to premises upon which facilities, buildings or portions of buildings are hereafter constructed or moved into or within the jurisdiction. If the water supply is inadequate, then a fire pump is needed to improve the water supply pressure and resulting flow.

Typical Fire Pumps Horizontal Split Case (HSC) Fire Pump

Typical Fire Pumps Vertical Inline Fire Pump

Not So Typical Fire Pumps Vertical Shaft Turbine Pump

Not So Typical Fire Pumps Positive Displacement Pump

Cornell University How does a pump work?

Fire Pumps Typical Applications: High-rise & partially sprinklered buildings Automatic standpipe Per NFPA 14

Fire Pumps

Fire Pumps Typical Applications: Where sprinkler demands are above average: Storage

Fire Pumps Typical Applications: Where sprinkler demands are above average: Industrial and high hazard facilities

Fire Pumps Typical Applications: Where water supply is inadequate:

Fire Pumps Typical Assembly in a Horizontal Split Case (HSC) Fire Pump

Fire Pumps What do pumps do? They increase (boost) pressure They circulate and lift water They increase water flow

Fire Pumps They boost pressure...

Fire Pumps They boost pressure... NET BOOST pressure is the difference between the discharge pressure and suction (or pump inlet) pressure.

Fire Pumps They boost pressure...

Fire Pumps They lift water...

Fire Pumps And they increase flow...

Fire Pumps Factory Pump Curve

Fire Pumps Cavitation Occurs when pump inlet pressure is too low (from obstructions or dist. system issues). Bubbles form at impeller inlet. Bubbles move to impeller outlet and collapse, causing a miniature shockwave. Can damage pump impeller and casing.

Fire Pumps Cavitation Prevented by keeping inlet pressure above the Net Positive Suction Head (NPSH). NPSH is identified as a line on the pump curve. As flow increases, so does the NPSH.

Fire Pumps NPSH

Fire Pumps TRUE OR FALSE? A fire pump s normal inlet pressure is 50 PSI. When the pump inlet pressure falls to 25 PSI, the pump fails its flow test.

Fire Pumps FALSE

Fire Pumps Varying inlet pressure affects discharge pressure. The net boost pressure is what s being measured during the annual test, not discharge pressure. Boost pressure should always be the same regardless of street-side pressure.

Questions??

PART 4 FIRE PUMP TESTING CODE REQUIREMENTS AND PRACTICES

Code Requirements Related to Fire Pumps Goals Learn about fire pump testing codes Learn about what tests are performed Learn about the testing equipment Learn about measurement accuracy

Code Requirements Related to Fire Pumps Per 2010 FCNYS, section 508.1 (507.1 in 2015), Required Water Supply: An approved water supply capable of supplying the required fire flow for fire protection shall be provided to premises upon which facilities, buildings or portions of buildings are hereafter constructed or moved into or within the jurisdiction. If the water supply is inadequate, then a fire pump is needed to improve the water supply pressure and resulting flow.

Code Requirements Related to Fire Pumps Per 2010 & 2015 FCNYS, section 913.1, where provided, fire pumps shall be installed in accordance with this section and NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection. Per 2010 & 2015 FCNYS, section 913.5.1, an acceptance test is required and done in accordance with NFPA 20. Verifies pump performance matches factory curve. Baseline of performance over life of pump.

Code Requirements Related to Fire Pumps After installation, fire pumps must be inspected, tested and maintained periodically. Per FCNYS, section 913.5, ongoing testing shall be done in accordance with NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems

Code Requirements Related to Fire Pumps Weekly testing requirements per NFPA 25-08 & 25-14, section 8.3.1 10 minutes for electric drivers (8.3.1.2) 30 minutes for diesel drivers (8.3.1.3) 25-14, 8.3.1.2.2 & 8.3.1.2.3 Exceptions for electric pumps Annual testing per NFPA 25-08 & 25-14, section 8.3.3 Measure flow, net pressure and driver characteristics at churn, 100%, 150% and 100% on EM power.

Code Requirements Related to Fire Pumps Why test? NFPA 25-08, section 8.3.5.3 (8.3.7.3 in 25-14) says a pump is impaired if it s performing below 95% of it s specified performance. It must be repaired Testing verifies performance. Trending pump performance can help predict failure before it happens.

Code Requirements Related to Fire Pumps Why test?

Code Requirements Related to Fire Pumps Why test? To verify nothing else is wrong In a three year period, Cornell EH&S had identified (9) fire pumps operating below 95% of design flow, through testing

Code Requirements Related to Fire Pumps Upson Hall Fire Pump 1985 75 PSI @ 750 GPM

Code Requirements Related to Fire Pumps When the first pump was opened up, casing and impeller appeared normal.

Code Requirements Related to Fire Pumps Rebuilt No change New impeller +1 psi gain New casing 100%!

Code Requirements Related to Fire Pumps Theories related to failure included: Street pressure too low. Convoluted and extremely long test header.

Code Requirements Related to Fire Pumps Conclusions: Corrosion-related casing wear. Easier and less expensive to replace entire casing and rotating assembly unit if there are no visual signs of obstruction or casing loss.

Code Requirements Related to Fire Pumps Bradfield Hall Fire Pump 2001 150 PSI @ 1250 GPM

Code Requirements Related to Fire Pumps

Code Requirements Related to Fire Pumps Comstock Hall

Code Requirements Related to Fire Pumps Testing - what s involved? Simply measuring flow and pressure At churn, 100%, 150% and 100% on emergency power. Measuring driver characteristics: Electric - rpm, volts, amps. Diesel rpm, amps, oil pressure.

Code Requirements Related to Fire Pumps What s involved? Flow can be measured with: Playpipes and a handheld pitot

Code Requirements Related to Fire Pumps What s involved? Flow can be measured with: Hose Monster with pitot & gauge

Code Requirements Related to Fire Pumps What s involved? Flow can be measured with: Hose Monster with a Pitotless nozzle & gauge

Code Requirements Related to Fire Pumps What s involved? Flow can be measured with: In-line flow meter

Code Requirements Related to Fire Pumps Playpipes are the least convenient and can lead to less accurate results.

Code Requirements Related to Fire Pumps Need to point in the right direction

Code Requirements Related to Fire Pumps Hand-held Pitot

Code Requirements Related to Fire Pumps Playpipes in action

Code Requirements Related to Fire Pumps Hose Monster diffuses flow and improves flow measurement. Employs a calibrated pitot (or nozzle) and pressure gauge connection.

Code Requirements Related to Fire Pumps Hose Monster Pitot

Code Requirements Related to Fire Pumps Pitotless Nozzle-equipped Hose Monster Direct-attached gauge

Code Requirements Related to Fire Pumps Hose Monster Nozzle

Code Requirements Related to Fire Pumps 1¾"

Code Requirements Related to Fire Pumps Inline flow meter

Code Requirements Related to Fire Pumps Pressure is also measured on the inlet and outlet of pump. Net pressure = discharge - suction

Code Requirements Related to Fire Pumps Gauges For fire pump testing, gauges need to accurate NFPA 20-07 does not explicitly dictate accuracy for general purpose or field gauges NFPA 20-07, section 14.2.7.1.2 (14.2.6.1.2.2 in 20-13) does call for +/- 1% for calibration of field test gauges NFPA 25-08, section A.8.3.5.1 (A.8.3.7.1 in 25-14) calls for +/- 1% accurate gauges

Code Requirements Related to Fire Pumps Gauges +/- ½% or better accuracy is ideal Inaccurate gauges could fail a fire pump when it s still above 95% Accuracy reduces need for re-testing

Code Requirements Related to Fire Pumps Gauges Fluid-filled analogue or Digital, you pick. Both are ½% accurate over a 100 psi range.

Code Requirements Related to Fire Pumps Driver Measurements Electric and diesel driver measurements verify proper operation. Per NFPA 20-07, section 10.3.4.4 (10.3.4.3 in 20-13), +/- 5% for voltage and current is acceptable. Per NFPA 20-07 and 20-13, section 9.5.2.1 and 9.5.2.2, motor amps cannot exceed the rated amperage multiplied by the service factor (usually 1.15) Electric and diesel drivers exceeding voltage and current limits (or rpm) could destroy the driver.

Code Requirements Related to Fire Pumps Part 4 Summary FCNYS Chapter 9 refers to: NFPA 20 for installation and acceptance testing requirements NFPA 25 for inspection, testing and maintenance requirements Testing involves measuring flow, pressure and driver characteristics Flow measurement devices include: Playpipes & hand-held pitos Flow diffusers with pitos Flow diffusers with Pitoless Nozzles Inline flow meters

Code Requirements Related to Fire Pumps Part 4 Summary Pressure gauges need high quality and as accurate as possible Good gauges reduces: Chances of error False Positives Retesting

Questions?

PART 5 PRECAUTIONS & LESSONS LEARNED

Precautions & Lessons Learned Some things to keep in mind before and during a flow test.

Precautions & Lessons Learned Verify instruments are calibrated and undamaged before every test. Are needles all at Zero?

Precautions & Lessons Learned Verify instruments are calibrated and undamaged before every test. Are pitot openings perfectly round and/or unbent?

Precautions & Lessons Learned Verify instruments are calibrated and undamaged before every test. Any leaks in gauge tubing or fire hoses?

Precautions & Lessons Learned What can happen with a bad gauge: Pump rated at 65 PSI net boost @ 100% flow. Suction gauge reads 40 PSI. Discharge gauge reads 100 PSI. 95% cutoff is 61.75 PSI net boost. Gauges reveal 60 PSI net boost. Re-tested with new gauges: Suction 40 PSI Discharge 102 PSI Net boost now 62 PSI. First gauge was reading low by 2 PSI!

Precautions & Lessons Learned Another example of a bad gauge: Unknowingly, pitot gauge is reading 5 PSI high. When its really 15 PSI, it s reading 20 PSI. T&I team choke flow down to achieve 15 PSI to get 425 GPM. Since real pressure is now at 10 PSI, flow is really 347 GPM, not 425 GPM, and will indicate a higher boost pressure on the curve. An extra set of gauges or semi-annual recalibration helps minimize error potential.

Precautions & Lessons Learned Don t measure pitot or nozzle pressures below the minimum pressure on the chart. The reading will be inaccurate, and could result in a failed pump that s not really impaired.

Precautions & Lessons Learned 1¾"

Precautions & Lessons Learned If there are two methods of testing available, use one to check the calibration of the other. Pitot to check in-lines and vice versa. If both provide same results, then assume both are properly calibrated. If results not identical, use process of elimination rule out bad device. Take away - Bad gauges, damaged pitots, leaky hoses can lead to an impaired pump.

Precautions & Lessons Learned ALWAYS flush system before testing. Rocks could damage pitots. Scale could clog pitots and in-line flow meter ports. ALWAYS make sure pitots are pointed backward during flush.

Precautions & Lessons Learned Be aware of elevation differences between discharge point and flow device gauge locations. A 12-foot elevation difference would create a 5 PSI error, possibly leading to an impaired pump.

Precautions & Lessons Learned Remote gauge

Precautions & Lessons Learned Know where to discharge water to. A 1,000 GPM pump could equal roughly 20,000 gallons worth of destroyed landscaping.

Precautions & Lessons Learned

Precautions & Lessons Learned Per NFPA 25-08, section 8.3.3.2 (8.3.2.9 in 25-14), ALWAYS check packings prior to runs. Packings need to drip! Dry packings will burn up if tightened too much. Loose packings could lead to slight performance drop.

Precautions & Lessons Learned Typical Fire Pump Rotating Assembly

Precautions & Lessons Learned Weill Hall fire pump Over-tightened packing

Precautions & Lessons Learned Per NFPA 25-08, section 8.3.3.2 (8.3.2.9 in 25-14), ALWAYS verify casing relief valve is open prior to runs. Water flow during churn should be visible. A closed relief valve could cause water in pump to overheat and boil.

Precautions & Lessons Learned Per NFPA 25-08, section 8.3.3.2 (8.3.2.9 in 25-14), ALWAYS verify casing relief valve is open prior to runs. Cavitation is boiling water!

Precautions & Lessons Learned Per NFPA 25-08 and 25-14, section 8.3.3.3, always close main relief before testing. Churn and lower-flow pressures won t match factory test curve if valve is allowed to open. Don t forget to open valve after test and reflow to make sure valve opens and closes at the correct settings.

Precautions & Lessons Learned Employ gauges on hydrant nearest the pump. AWWA calls for minimum distribution system residual pressure of 20 PSI. If pump inlet is below 20 psi at 150% flow, and hydrant gauge is not, 150% test can continue. Unusually high pressure delta between hydrant and pump could indicate an obstruction or undersized piping. Helps to diagnose low pump inlet pressure situations.

Precautions & Lessons Learned Sometimes, pumps fail the acceptance test or annual tests!

Precautions & Lessons Learned This could be due to something other than the pump or driver. Be aware of how much fire hose is used. NFPA 20-07, section A.14.2.7.2.1 (A.14.2.6.1 in 20-13), hose length shall be minimized. Too much hose can lead to lower than acceptable flow at 150%. Each 50-ft. length of 2 ½ hose creates around 6 PSI of resistance at 250 GPM.

Precautions & Lessons Learned This could be due to something other than the pump or driver. Simple way to check If test header hose valves are full open and flow is not achieved, then there is extra resistance somewhere in the flow path. If the hose valves need to be partially closed to achieve required flow, then pump is providing more pressure than is consumed by the header and hoses.

Precautions & Lessons Learned This could be due to something other than the pump or driver. If current test pressures are higher than last year s, that s a clue that something is not right. Compare current readings to the last two years, if possible. A pump will never get better, only worse.

Precautions & Lessons Learned Valid readings?

Code Requirements Related to Fire Pumps TRUE OR FALSE? Excessive elevation difference between nozzle and pressure gauge will affect reading.

Code Requirements Related to Fire Pumps TRUE

Code Requirements Related to Fire Pumps For each foot of elevation change, the gauge will vary by 0.43 PSI A gauge manifold located on a hill 10 feet above the hose monster nozzle will read 4.3 PSI lower than the actual If a pump was operating at 97 PSI (out of 100 PSI), gauge would read 92.7 PSI Pump would be incorrectly identified as impaired

Code Requirements Related to Fire Pumps What s the deal with over-amping? Motors are rated for a maximum amperage. On occasion, cavitation will occur. And amps will increase. Why is this?

Code Requirements Related to Fire Pumps What s the deal with over-amping? Electric motor horsepower increases when it s doing more work. More flow equates to more work. No flow equates to less work.

Code Requirements Related to Fire Pumps What s the deal with over-amping?

Code Requirements Related to Fire Pumps What s the deal with over-amping? So, amps are lower at churn than during flow. Pump is designed so amps do not exceed max. amp rating at or below 150% under normal inlet conditions.

Code Requirements Related to Fire Pumps What s the deal with over-amping?

Code Requirements Related to Fire Pumps Data plates and NFPA 20-07 & 20-13 Section 14.2.4.1 states that the certified factory test curve shall be available to compare acceptance test results to.

Code Requirements Related to Fire Pumps Be aware of when you test Cold weather is not kind to testing

Questions??

One last thing. Have you seen this before?

Tom Jordan tej2@cornell.edu 607.255.9728 607.339.3549