SF Sizes

[65mustang393]

Measured the 300 cfm plate diameter, cfm and airspeed.

Intake setting.
I measured the Plate at 2.044" diameter. 3.2813 sq inches of area.
289.4 cfm

289.4 x 2.4 = 694.56
694.56 divided by 3.2813 = 211.7 fps.

I got 207.3 fps. It was a PITA holding the pitot.

[Brucepts]

SF orifice plate it's a large picture!

[1960FL]

Check this out, straight from the SF600 manual...

The values for all ranges are shown on the Calibration Data Card mounted on your SF-300/600
flowbench for 25” (60cm) of test pressure.

Important Note: The SF-300/600 flow ranges are based on a test pressure of 25”(63.5cm) of
water. If other test pressures are used, the flow scale calibration ranges should be corrected by
the following amounts.

I then put my 2.250 plate (356 calibrated cfm w/electronics) and it showed 78.2% of 442.9cfm = 346.3 cfm

Chad can you please flow the 2.25 plate at 25" I am having a hard time believing that there cal plate CFM only moves CFM/.997 moving test pressure from 25 to 28

if this is so your 2.250 plate should read 345.3 at 25

Please remember i am using the correction number Gerald posted not sure if your manual read the same.

Rick

[Chad Speier]

Bruce, my disk is gold..

A 2.044 plate would be set to flow 293.7 cfm on my bench. (13.29 x DIA²) x SQROUTE of test pressure.

[Chad Speier]

Check this out, straight from the SF600 manual...

The values for all ranges are shown on the Calibration Data Card mounted on your SF-300/600
flowbench for 25” (60cm) of test pressure.

Important Note: The SF-300/600 flow ranges are based on a test pressure of 25”(63.5cm) of
water. If other test pressures are used, the flow scale calibration ranges should be corrected by
the following amounts.

I then put my 2.250 plate (356 calibrated cfm w/electronics) and it showed 78.2% of 442.9cfm = 346.3 cfm

Chad can you please flow the 2.25 plate at 25" I am having a hard time believing that there cal plate CFM only moves CFM/.997 moving test pressure from 25 to 28

if this is so your 2.250 plate should read 345.3 at 25

Please remember i am using the correction number Gerald posted not sure if your manual read the same.

Rick

Rick

It flowed 334.2 cfm @ 25" w/FP
It flowed 73.6% manometer @ 442.2 = 325.5 cfm

My 2.250 plate is set to read 356 cfm @ 28"
2.250 = 3.98 in²
3.98in² - pitot diameter = 3.964 / 356 x 2.4 = 215.5 fps
Pitot measures 216.8 fps

[hdwgfx]

SF orifice plate it's a large picture!

Bruce, what SF machine uses this disc???

[65mustang393]

Pic of SF cal range correction chart.

[65mustang393]

SF orifice plate it's a large picture!

Bruce, what SF machine uses this disc???

SF300/600 models use that style disc.

[1960FL]

Rick

It flowed 334.2 cfm @ 25" w/FP
It flowed 73.4% manometer @ 422.2 = 309.9 cfm

Chad did you mean to use 442.2 your range calibration

73.4% * 442.2 = 324.6.

Please help me here but in this quote,

The values for all ranges are shown on the Calibration Data Card mounted on your SF-300/600
flowbench for 25” (60cm) of test pressure.

Important Note: The SF-300/600 flow ranges are based on a test pressure of 25”(63.5cm) of
water. If other test pressures are used, the flow scale calibration ranges should be corrected by
the following amounts.

I read this as they say there calibration number in your case #5 442.2 is derived at 25" test pressure.

What does it say next "Following amounts"

Rick

[65mustang393]

Bruce, my disk is gold..

A 2.044 plate would be set to flow 293.7 cfm on my bench. (13.29 x DIA²) x SQROUTE of test pressure.

It's the 300 cfm PAP I bought as a set from Bruce.