This article will guide you through PVC Ductwork Sprinkler Model installation and maintenance procedures. Installation should take approximately 10-20 minutes per head. (Not Including cure time.)
Please view warnings and cautions before installation.
Part I – Installation of Bottom Mounting Block
- FlexHead® Location
Determine desirable location for FLEXHEAD unit in ductwork. FLEXHEAD unit must be accessible for periodic inspection. For recommended guidelines and standards for protection systems in industrial exhaust systems see Factory Mutual loss prevention data sheets 7-78, article 2-4. Once desired location is determined drill a two-(2) inch hole in duct with hole saw.
- Mounting Bottom Block – Method #1
- Remove any ragged edges or burrs from 2” hole in duct. Clean 6” by 6” square area around hole in duct of dirt, grease, and moisture.
- Apply PVC primer evenly and freely to 6” by 6” area around 2” hole in duct, using supplied dauber applicator.
- Apply PVC primer to bottom of FlexHead® PVC mounting block evenly and freely using supplied dauber applicator.
- Apply a full even layer of cement on the 6” x 6” prepared area on duct with supplied dauber applicator. Apply a full even layer of cement on bottom curvature of FlexHead® mounting block. Cement layers must be without voids and sufficient to fill any gap between duct and mounting block. Place PVC mounting block on prepared area on ductwork, immediately, making sure 2” hole in duct and 2” hole in mounting block are aligned. Assemble without delay while cement is still wet. Hold mounting block on duct firmly for about 30 seconds or until cement has begun to cure. With a rag, wipe away any excess cement from four sides of mounting block. Avoid disturbing the joint.
- Allow 15 minutes for good handling strength. Cure times will vary depending on size, temperature, etc. Consult PVC cement manufacturer’s directions for additional details. If any problems exists with industrial strength PVC cement during the installation, use air weld method of installation – method #2 on following page.
- Mounting Bottom Block – Method #2
Place FlexHead® bottom mounting block on duct. Align 2” hole in ductwork with 2” hole on FLEXHEAD bottom block. With plastic welding torch ‘tack’ FlexHead® bottom mounting block on to ductwork on all four sides of block. Air weld FlexHead® bottom mounting block on to ductwork on all four sides following welding manufacturer’s guidelines and recommendations. (A minimum of three welds on each side of FLEXHEAD block is required.) For additional information call (800) 829-6975 or (978) 264-0822.
Part II – Installation of Top Mounting Block
- Connect FlexHead® to Sprinkler System
Connect one-(1) inch stainless steel flexible hose of FLEXHEAD to one-(1) inch black iron pipe union of fire protection system in accordance to NFPA standards, state and local codes.
- Connect Top Mounting Block
Place top FLEXHEAD mounting block onto previously installed bottom mounting block with gasket. Make sure that sprinkler head section of the FLEXHEAD unit is inserted into two-(2) inch hole in duct, and that the four-(4) stainless steel bolts of bottom mounting block align with corresponding bolt holes in top mounting block. Angle of flexible hose should not exceed 90°.
Place one-(1) stainless steel washer and one-(1) stainless steel nut onto each of the four-(4) stainless steel bolts. Tighten each of the nuts hand tight onto the block. Tightening process of nuts onto the mounting block should be done in a diagonal process to ensure equal distribution of pressure throughout the mounting block. Nuts should be tightened to 15 in.-lb. using a torque wrench. DO NOT OVER TIGHTEN NUTS ONTO BLOCK. Installation of FLEXHEAD is complete.
Inspection of PVC Ductwork Model Sprinkler Head
- Once fire protection and exhaust system are inactive, proceed with inspection of FLEXHEAD unit.
- Remove the four-(4) stainless steel nuts and washers from top mounting block.
- Now lift top mounting block from bottom mounting block and bolts, by holding onto base of stainless steel hose.
- Inspect sprinkler head and polybag section of FLEXHEAD. IF DAMAGE EXISTS IN OUTER POLYBAG ONLY, REPLACE BOTH BAGS AT THIS TIME. If damage exists through both polybags remove remainders of polybags and inspect wax coated sprinkler head. IF ANY DAMAGE EXISTS IN SPRINKLER HEAD REPLACE HEAD AND BOTH POLYBAGS AT THIS TIME in accordance to NFPA regulations and guidelines. To order additional gasket/dual polybag assemblies call (800) 829-6975 or (978) 264-0822.
- Once inspection and maintenance of FLEXHEAD has been completed, reinsert top mounting block onto bottom block aligning corresponding sprinkler head and bolt holes.
- Replace the four-(4) stainless steel washers and nuts onto the four-(4) stainless steel bolts accordingly. Hand tighten each of the four-(4) nuts onto the block. The tightening sequence of nuts onto the mounting block should be done in a diagonal manner to ensure equal distribution of pressure throughout the mounting block. Nuts should be tightened to 15 in.-lb. using a torque wrench. DO NOT OVER TIGHTEN NUTS ONTO BLOCK. MAINTENANCE OF FLEXHEAD IS COMPLETE.