Canadian Flag


Foreign Exchange Calculator
Foreign Exchange
Calculator --
Courtesy of
TD Securities



Send Email



Visa accepted
Master Card accepted
American Express accepted
Discover Card accepted
One Stop Fire Products One Stop Fire Products One Stop Fire Products
Fire Fighting Pumps For Your Farm, Camp or Cottage!


LIFT & HEAD

Lift, Head & Flow

Pump manufacturers document the performance of their pumps in several ways. LIFT & HEAD are used to rate the ability to move water vertically while FLOW reflects the quantity of liquid that can be moved in a given amount of time.

Liquid Pump Terminology

Discharge Head
This is the vertical distance that you are able to pump the liquid. Say your pump is rated for a maximum head of 100 feet, this does not mean that you are restricted to100 feet of pipe, you could use 300 feet, so long as the final discharge point is not higher than 100 feet above the liquid being pumped.
Suction Lift
This is the vertical distance that the pump can be above the liquid source. Typically, atmospheric pressure limits vertical suction lift of pumps to 25 feet at sea level (see chart below). This does not mean that you are limited to 25 feet of pipe, you could use upwards of 200 feet of suction pipe, so long as the liquid source is not lower than 25 feet below the pump center line.
Total Head
Sum of discharge head, suction lift, and friction loss.
Friction Head
Pressure expressed in Lbs. that is required to overcome the resistance to the flow in the pipe system. (see section below)

In a general conversation about the performance abilities of a pump, the term head usually refers to the maximum vertical distance from water source to discharge point that water can be pumped. Please note that at this limit, the pump can push the water no higher. This is a rating assigned by the manufacturers based on design technologies and benchmark testing. An individual pump may perform slightly above or below that mark. This rating should be used to compare pumps and help evaluate the pump's suitability for the application.


Various Units for HEAD

Different pump manufacturers express their head ratings in different units. One might state that the maximum head for a specific pump is 200 feet while a competetive pump is rated at 90 PSI. A third pump may give the head at 6 bar. Although sounding quite different, they are actually comparable. The chart below shows the relationship of the various units.

Head Conversion Factors:
1 psi = 2.31 feet head1 foot head = 0.433 psi

Head Reference Chart
FeetPSI MetresBar KPA
0000.00
20960.660
4017121.2120
6026181.8179
8035242.4239
10043303.0299
12052373.6359
14061434.2418
16069494.8478
18078555.4538
20087616.0598
22095676.6658
240104737.2717
260113797.8777
280121858.4837
300130919.0897
320139989.6956
34014710410.21016
36015611010.81076
38016511611.31136
40017312211.91196
42018212812.51255
44019113413.11315
FeetPSI MetresBar KPA
46019914013.71375
48020814614.31435
50021715214.91494
52022515815.51554
54023416516.11614
56024317116.71674
58025117717.31734
60026018317.91793
62026918918.51853
64027719519.11913
66028620119.71973
68029520720.32033
70030321320.92092
72031221921.52152
74032122622.12212
76032923222.72272
78033823823.32331
80034724423.92391
82035525024.52451
84036425625.12511
86037326225.72571
88038126826.32630
90039027426.92690


A Bit About Suction Lift

The vertical distance that a pump may be placed above the water level (and be able to draw water) is determined by pump design and limits dictated by altitude. The chart below shows the absolute limits. The closer the pump is to the water level, the easier and quicker it will be to prime.

Suction Lift at Various Elevations
Altitude: Suction Lift In Feet
Sea Level 25.0
2,000 ft. 22.0
4,000 ft. 19.5
6,000 ft. 17.3
8,000 ft. 15.5
10,000 ft. 14.3


Friction Head (Loss)

As water is pumped through hose or pipe, pressure is consumed (or lost) due to the friction of the water against the inner surface of the waterway. The amount of loss depends on many factors including nature of waterway surface, rate of water flow, diameter of hose, pressure, temperature as well as the straightness of the water path. Sounds complicated ??? Well it is.

Friction Head - Our 1½" Forestry Hose
Gallons/MinuteLoss in PSI/100'
100
202
302
404
506
Gallons/MinuteLoss in PSI/100'
607
709
8012
9015
10019

The 1½" hoses available on our website experience a pressure loss of about 0.07 psi/ft. based on a flow rate of 60 gpm. Very few products can boast a lower loss rate. Competitive hoses are rated at 0.09, 0.14 & 0.16 psi/ft. Older hoses, hose in disrepair or trash /junk hose may have ratings in the 0.20 - 0.30 psi/ft. range or higher -- based upon the same flow rate.

For general planning purposes, consider pressure loss to be 7 psi per 100 ft. length of hose @ 60 gpm. In theory, with a pump producing 100 psi, 1000 ft. of hose will leave you with 30 psi -- excluding elevation and other sources of head loss. If you restrict flow to 30 gallons per minute by using a different nozzle, then pressure loss becomes 2 psi per 100'. In this case, 1000 ft. of hose would leave you with 80 psi -- quite adequate for fire protection. In reality, the only way to get a true feeling of the effects of the various head loss factors is to actually perform tests in your setting.




One Stop Fire Products Inc.
Markham, Ontario
L3P 7H9
Canada
Tel: (905) 946-1033
Fax: (905) 946-1035
Bar

One Stop Fire Products is an InternetSecure Certified Merchant