DEPLOYING FST-250 CARTRIDGE

Stop Water Damage

Improve Electrical Reliability

Polywater® FST™ Foam Duct Sealant meets and exceeds the NEC section requirements for sealing conduit systems.  Polywater® FST™ is superior to both duct putty and aerosol cans of foam because it has been tested for cable compatibility; holds 22 feet of water head pressure continuously and up to 90 feet intermittently; prevents gas from passing through; does not sag; will not dry out; and is re-enterable.  FST™ sealant is chemically resistant to gasoline, oils, dilute acids and bases, and most unsaturated hydrocarbons.  Review the technical bulletin to see our extensive ASTM product testing: http://www.polywater.com/ductseal.html.

Know the Code!

The National Electric Code states that conduits and raceways should be sealed to prevent moisture, hazardous gases and vapors from entering buildings.  It also requires sealants to be compatible with cable jackets and other components. 

NFPA 70® National Electrical Code® 2011 Edition

225.27 Raceway Seal.  Where a raceway enters a building or structure from an underground distribution system, it shall be sealed in accordance with 300.5(G).  Spare or unused raceways shall also be sealed.  Sealants shall be identified for use with the cable insulation, shield, or other components.

230.8 Raceway Seal.  Where a service raceway enters a building or structure from an underground distribution system, it shall be sealed in accordance with 300.5(G).  Spare or unused raceways shall also be sealed. Sealants shall be identified for use with the cable insulation, shield, or other components.

300.5(G) Raceway Seals.  Conduits or raceways through which moisture may contact live parts shall be sealed or plugged at either or both ends.  Informational Note: Presence of hazardous gases or vapors may also necessitate sealing of underground conduits or raceways entering buildings.

Duct Putty and Canned Foam do not meet the NEC requirements.

The most widely used product to seal conduits is duct putty.  Duct putty is intended to seal around junction boxes and flashings.  When used in conduits, it sags over time and creates openings in seals when cables or wires are moved.  Putty holds minimal water head pressure, compresses under large cable weight, and typically has no test results for cable compatibility.  Putty seals routinely fail.

Canned foam is designed for cracks and crevices.  It creates a lightweight, open-cell structure that allows water and moisture to pass through, much like a sponge.  It will not completely cure in thick layers or enclosed spaces.  Its seal is not airtight or watertight.

Neither product should be used for construction purposes other than those originally intended.  Electrical inspectors can request that such products installed as raceway seals be removed!

TOP: SAGGING DUCT PUTTY,
MIDDLE: DUCT PUTTY GAPS,
BOTTOM: AEROSOL CAN OF OPEN-CELL FOAM

FST™ Water Blockage Performance

FST™ Sealant is an excellent water block.  It will seal active water leaks.

View a short video on how FST™ can stop 1 gallon/minute of water running through a conduit: http://www.youtube.com/watch?v=Ed0X1AfVyVE&feature=youtu.be

To test water-blocking performance, FST™ is installed in a conduit according to standard procedures, forming a 3-inch plug.  Water is added to the system and then pressurized to create a water head.  Additionally, blue dye is added to the water to allow detection if any penetrates the FST™ foam block.  FST™ sealant blocks considerable water head pressure, even when forces are placed on the cable to stress the seal.

Condition	Result
HDPE Duct, (SDR 13.5)   No Cables	Holds 7 days at 30 psi (70 feet of water)
PVC Conduit,   No Cables	Holds 450 days at 10 psi (22 feet of water)
PVC Conduit,   3 MDPE Cables	Holds 15 min at 40 psi (90 feet of water)
PVC Conduit,   3 MDPE Cables bent   45°, opposite directions   for 5 minutes	Holds 15 min at 40 psi (90 feet of water)
PVC Conduit,   3 MDPE Cables pulled   with 15 lbs. axial force   for 4 hours	Holds 15 min at 40 psi (90 feet of water)

FST™ WATER-BLOCK TEST

Seal Strength - Air and Other Gases - System Safety

Electric utilities, petro-chemicals and industrial facilities are all very concerned about worker safety and system integrity involving gas exposure or risk of explosions.  FST™ sealant blocks manhole gases.  To test seal strength, a 3-inch FST™ seal is installed in conduit according to standard directions.  The conduit is sealed and pressurized with both air and helium.  Helium is a small molecule less than half the size of methane gas, and was used in place of methane.

FST™ CURED IN CLEAR CONDUIT

Condition	Result
Air, 10 psi, 168 hours	Holds Seal
Helium, 5 psi, 72 hours	Holds Seal

Cable Compatibility

FST™ Sealant is compatible with common cable jacket materials.  It does not change physical tensile and elongation properties of the jacket.  Volume resistivity testing shows that FST does not affect the electrical property of cable while it is reacting and once it is cured.  The cured foam is an inert solid that does not affect cable components or the functionality of cable or wire.  Detailed testing reports are available upon request.  

How to Remove the FST™ Foam Block - Cable Removal

People often ask how to remove FST™ from the conduit.  First, de-energize the electrical system and take proper precautions to follow your company’s guidelines for working on electrical systems. Secondly, pull the foam damming strip out of the end of the conduit and place a flat head screwdriver tip on the inside edge of the conduit directly on the foam.  Next, hit the butt end of the screwdriver with a hammer and then twist the screwdriver in the foam seal.  Work your way around the conduit to break the seal and then pull your cables or wires out.  If you prefer, you can utilize cable pulling equipment to break the wires free of their bond instead.  Always use good cable pulling practices after removing your cables by running a mandrel through the conduit system to ensure that all contaminants have been removed from the conduit system.

Theft Deterrent Testing

 

Copper theft has increased recently due to its high scrap value.  FST™ Sealant acts as a theft deterrent by sealing cables into the conduit.  The seal makes it very difficult to remove the wires by hand.

FST™ CUT-AWAY

Installing FST™ at both ends of the conduit can double the pull-out force needed to remove the cables.  Some customers put a zip tie around a tag-out sign stating that these cables or wires are protected by an anti-theft system.  This further acts as a visual deterrent, as the thieves can see the FST™ surrounding the wires or cables along with the sign.  To test this, a 3-inch plug of FST™ is used to seal 3 cables in a conduit according to standard procedures.  The force to pull out each cable is measured.

Cable Type	Average Pull Out Tension (lbf)
2 AWG THHN	171
4/0 XHHW	320

 

 

Draka prelubricated HDPE Cable in Conduit (CIC)	Average Pull-Out Tension (lbf)
1-¼ inch with (2) RHW-2 awg cables and ground	188*
1-½ inch with (3) RHW-2 awg cables and ground	179*

*Entire foam core pulled out of the conduit.
 

Specifying the use of Polywater® FST™ Foam Duct Sealant helps keep switchgear, vaults, meters, hand holes, junction boxes, riser poles, and electrical equipment free from water damage and hazardous gas problems.

For further information please call us at 651-430-2270 and ask for extension #250 or e-mail us at custserv@polywater.com .

FST™ IN-FIELD SEALS