FEBCO Backflow Preventer Maintenance Checklist

When it comes to a FEBCO backflow preventer, routine maintenance should always be a priority. Technicians can stay on top of maintenance checklists so that units will be operating smoothly and safely. We will help you below with our FEBCO backflow preventer maintenance checklist with tips and steps for multiple sizes. 

The following guide is made for the FEBCO pressure vacuum breaker model 765.

Backflow Preventer Maintenance Checklist

Maintenance Tips

• Make sure to rinse all the parts before assembly
• Don’t use any pipe dope, oil, grease or solvent on any parts unless otherwise stated
• Don’t force parts during installation. The parts should fit together easily. Excessive force could cause damage and render the device inoperable
• Inspect the seals, seating surfaces, etc. for any damage or debris
• Test the unit after any servicing or maintenance to ensure it’s operating correctly
• Tighten the canopy nut only until it can’t turn freely
• Rapidly open the inlet ball valve to minimize spillage through the air vent. Slowly open the outlet ball valve.

1/2″ – 1-1/4″ Sizes Maintenance

• Step 1 – First close the outlet ball valve, then close the inlet ball valve. Bleed the residual pressure by opening the #2 testcock.
• Step 2 – Remove the canopy and nut. 
• Step 3 – Unscrew the bonnet assembly from the valve body by hand.
• Step 4 – Remove the poppet/seal assembly from the body.
• Step 5 – Evenly depress the retaining bracket 1/4″ and rotate the bracket 90 degrees.
• Step 6 – Remove the bracket, spring and check assembly.
• Step 7 – Remove the screw that’s holding the guide and lift the seal from its holder. Be careful not to damage the guide legs or the guide pin of the holder.
• Step 8 – Insert the seal disc into the holder. Position the guide in the center of the seal and thread the retaining screw through the guide into the holder.
• Step 9 – Lightly tighten the screw to hold the guide from rotation, making sure not to overtighten. 
• Step 10 – To reassemble, position the check assembly into the valve body. Position the spring into the recessed area on the top side of the check assembly.
• Step 11 – Install the retaining bracket, making sure the spring is centered around the base of the bracket.
• Step 12 – Roll the rubber disc into the recess on the poppet and position the poppet assembly in the valve body.
• Step 13 – Apply a thin coat of Vaseline on the o-ring. Don’t use any other lubricant.
• Step 14 – Ensure the guide pin of the bonnet correctly enters the hole in the poppet.
• Step 15 – Thread the bonnet by hand into the valve body until the bonnet flange bottoms on the top surface of the valve body. Don’t over tighten.
• Step 16 – Tighten the canopy nut only until the canopy can’t turn freely. 
• Step 17 – Rapidly open the inlet ball valve to minimize spillage through the air vent. Slowly open the outlet ball valve. 

1-1/2″ – 2″ Sizes Maintenance

• Step 1 – First close the outlet ball valve, then close the inlet ball valve. Bleed the residual pressure by opening the #2 testcock.
• Step 2 – Remove the six bonnet bolts and lift the bonnet from the valve body. Remove the poppet and seat disc.
• Step 3 – To replace the poppet spring, unscrew the nut and guide pin and remove the spring. Be careful not to damage the guide pin.
• Step 4 – Install the new spring. 
• Step 5 – Remove the spring retaining web, spring and check assembly.
• Step 6 – Remove the guide retaining nut and guide, then lift the seal from the holder.
• Step 7 – Insert the new seal, position the guide in the center of the holder/seal and thread the nut. Lightly tighten the nut to hold the guide from rotating.
• Step 8 – To reassemble, position the check valve assembly, spring and retaining web into the valve body. Ensure the arms of the retaining web are aligned with the guide and supports in the valve body.
• Step 9 – Roll the rubber disc into the recess on the poppet and position the poppet assembly in the retaining web. 
• Step 10 – Place the bonnet on the valve body. Ensure the retaining web is properly supported by the three case bosses inside the bonnet.
• Step 11 – Insert the bonnet bolts and tighten.
• Step 12 – Rapidly open the inlet ball valve to minimize spillage through the air vent. Slowly open the outlet ball valve.