Amarillo Chittom AirFlo PowerFlo Blade Installation

Installation Instructions

PowerFlo™ Fans

3.0 Blade Installation ...

The blade clamps are different for the air intake side of the fan and the air discharge side. The two parts can be identified by the depth of the cut for the blade shank shoulder.
The cut is deeper on the air discharge side to produce a droop in the installed fan blade.

Place one of each clamp around the shank of the blade as shown.
Hold the blade so that the clamp with the deeper shoulder cut is to the discharge side of the fan and tip of the fan blade is angled slightly towards the air intake side of the fan.

The clamps should easily slide between the two plates of the fan hub.

Caution - If the clamps do not slide freely between the plates, check to see that you do not have either two intake side clamps or two discharge side clamps.

Recommended practice for tightening bolted joints is to hold the bolt head still while turning the nut. Therefore, it is a good idea to make sure the nuts are on the side of the hub easiest to access with the torque wrench. If not, remove them one at a time and switch them before all the blades are installed.

Installing spacer rings to reduce the fan diameter for proper tip clearance will decrease fan performance slightly. Better fan performance will be achieved if the fan ring can be increased in size instead of reducing the fan diameter.
Line up one of the holes in the plates and blade clamps. Place a blade clamp bolt through a flat washer and insert the bolt through the hole that is lined up in the clamps and plates. Place another flat washer on the blade clamp bolt and start the self-locking nut on the bolt finger tight.
Swing the blade around until the second set of holes lines up between the plates and clamps. Install the second blade clamp bolt finger tight with a flat washer under both the bolt head and the nut.

Slide the blade shoulder firmly against the clamps and tighten the blade clamp bolts just enough that the blade does not slide in the clamps.

Rotate the blade around the circumference of the fan ring to make sure there is proper tip clearance all the way around.

If necessary because of interference with the fan ring, spacer rings have been shipped with your fan assembly to reduce the fan diameter. Determine how much the blade must be moved in to provide proper tip clearance. Each spacer ring will reduce the fan radius (i.e. increase tip clearance) by 1/8 inch. A maximum of three spacer rings may be installed on each fan blade.

To install spacer rings, loosen the single blade installed in the hub. Slide the blade towards the center of the hub and snap the required number of spacer rings over the blade shank.

Pull the blade out radially so the spacer rings are firmly "sandwiched" between the blade shank shoulder and the back side of the blade clamp. Tighten the bolts enough to keep the blade in position and rotate the blade again to verify proper tip clearance all the way around.
Install the rest of the fan blades in the hub repeating the procedure used for the first blade.

Install the same number of spacer rings on every fan blade. Failure to maintain consistency in the number of spacer rings on each blade will result in increased vibration and stress.

For vertical applications, it might be easier to install blades in opposite sockets so that the weight remains balanced as much as possible during installation.

Mark a location on the fan ring where each blade will be pitched. For vertical applications this will either be at the three o'clock or nine o'clock position, depending on direction of rotation.

Loosen the blade clamp hardware just enough that the blade can be rotated in the blade clamps. Line up the trailing edge with your reference mark you just made on the fan ring.
At a position one inch from the blade tip, lay a straight edge across the trailing edge of the fan blade and the high point of the blade airfoil. Rotate the blade in the clamps until you get the right pitch.

Caution - The blades should be adjusted in pitch until the target value is achieved plus or minus 1/4 degree. Failure to rotate each blade to the same position for adjustment of the blade pitch can result in excessive variation between blades. Excessive pitch variation may result in vibration and high stress levels in the fan or surrounding equipment.

Caution - Excessive tip track may lead to high vibration levels in the fan or surrounding equipment. Stress in the fan blade and hub will increase with excessive tip track. Torque the blade clamp hardware to 50 ft. lbs for 1/2" bolts or 90 ft. lbs. for 3/4 inch bolts. Tighten one nut a turn or two and move over to the other bolt for a turn or two, switching back and forth until the proper torque is reached and maintained on both nuts.
Recheck the blade pitch at the position one inch in from the tip to make sure it has not changed during tightening of the blade clamp hardware.

Repeat this process for each fan blade, rotating them one at a time to the same position in the fan ring and setting the pitch on the blade.

Locate a convenient place in the fan ring to check the tip track of the fan blades.

Place a mark in the fan ring at the trailing edge of the fan blade parallel to the rotation of the fan blade in the ring.

Rotate each blade to the same position in the fan ring, mark and number the location of the trailing edge for each blade.

If the distance between the two outer marks is greater than 1/2 inch, identify the blade that is different. Loosen that blade and move the blade in the desired direction. Retorque the blade clamp hardware.

Recheck the pitch of the blade that tip track adjustment was made to and recheck the tip track of all blades. Repeat the process as necessary.

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AMARILLO CHITTOM AIRFLO
728 South Wheeling • Tulsa, OK 74104 USA
Phone: (918) 585-5638 • Fax: (918) 587-3577
E-mail: info@amarillochittom.com

	The blade clamps are different for the air intake side of the fan and the air discharge side. The two parts can be identified by the depth of the cut for the blade shank shoulder. The cut is deeper on the air discharge side to produce a droop in the installed fan blade.
	Place one of each clamp around the shank of the blade as shown. Hold the blade so that the clamp with the deeper shoulder cut is to the discharge side of the fan and tip of the fan blade is angled slightly towards the air intake side of the fan. The clamps should easily slide between the two plates of the fan hub.
Caution - If the clamps do not slide freely between the plates, check to see that you do not have either two intake side clamps or two discharge side clamps. Recommended practice for tightening bolted joints is to hold the bolt head still while turning the nut. Therefore, it is a good idea to make sure the nuts are on the side of the hub easiest to access with the torque wrench. If not, remove them one at a time and switch them before all the blades are installed. Installing spacer rings to reduce the fan diameter for proper tip clearance will decrease fan performance slightly. Better fan performance will be achieved if the fan ring can be increased in size instead of reducing the fan diameter.	Line up one of the holes in the plates and blade clamps. Place a blade clamp bolt through a flat washer and insert the bolt through the hole that is lined up in the clamps and plates. Place another flat washer on the blade clamp bolt and start the self-locking nut on the bolt finger tight. Swing the blade around until the second set of holes lines up between the plates and clamps. Install the second blade clamp bolt finger tight with a flat washer under both the bolt head and the nut. Slide the blade shoulder firmly against the clamps and tighten the blade clamp bolts just enough that the blade does not slide in the clamps. Rotate the blade around the circumference of the fan ring to make sure there is proper tip clearance all the way around. If necessary because of interference with the fan ring, spacer rings have been shipped with your fan assembly to reduce the fan diameter. Determine how much the blade must be moved in to provide proper tip clearance. Each spacer ring will reduce the fan radius (i.e. increase tip clearance) by 1/8 inch. A maximum of three spacer rings may be installed on each fan blade. To install spacer rings, loosen the single blade installed in the hub. Slide the blade towards the center of the hub and snap the required number of spacer rings over the blade shank.
	Pull the blade out radially so the spacer rings are firmly "sandwiched" between the blade shank shoulder and the back side of the blade clamp. Tighten the bolts enough to keep the blade in position and rotate the blade again to verify proper tip clearance all the way around. Install the rest of the fan blades in the hub repeating the procedure used for the first blade. Install the same number of spacer rings on every fan blade. Failure to maintain consistency in the number of spacer rings on each blade will result in increased vibration and stress. For vertical applications, it might be easier to install blades in opposite sockets so that the weight remains balanced as much as possible during installation. Mark a location on the fan ring where each blade will be pitched. For vertical applications this will either be at the three o'clock or nine o'clock position, depending on direction of rotation.
	Loosen the blade clamp hardware just enough that the blade can be rotated in the blade clamps. Line up the trailing edge with your reference mark you just made on the fan ring. At a position one inch from the blade tip, lay a straight edge across the trailing edge of the fan blade and the high point of the blade airfoil. Rotate the blade in the clamps until you get the right pitch.
Caution - The blades should be adjusted in pitch until the target value is achieved plus or minus 1/4 degree. Failure to rotate each blade to the same position for adjustment of the blade pitch can result in excessive variation between blades. Excessive pitch variation may result in vibration and high stress levels in the fan or surrounding equipment. Caution - Excessive tip track may lead to high vibration levels in the fan or surrounding equipment. Stress in the fan blade and hub will increase with excessive tip track.	Torque the blade clamp hardware to 50 ft. lbs for 1/2" bolts or 90 ft. lbs. for 3/4 inch bolts. Tighten one nut a turn or two and move over to the other bolt for a turn or two, switching back and forth until the proper torque is reached and maintained on both nuts. Recheck the blade pitch at the position one inch in from the tip to make sure it has not changed during tightening of the blade clamp hardware. Repeat this process for each fan blade, rotating them one at a time to the same position in the fan ring and setting the pitch on the blade. Locate a convenient place in the fan ring to check the tip track of the fan blades. Place a mark in the fan ring at the trailing edge of the fan blade parallel to the rotation of the fan blade in the ring. Rotate each blade to the same position in the fan ring, mark and number the location of the trailing edge for each blade. If the distance between the two outer marks is greater than 1/2 inch, identify the blade that is different. Loosen that blade and move the blade in the desired direction. Retorque the blade clamp hardware. Recheck the pitch of the blade that tip track adjustment was made to and recheck the tip track of all blades. Repeat the process as necessary.