Heat Shrink Tubing (Medium Wall)

MWTM Heat Shrink Tubing

MWTM Medium Wall Shrink Tubing

     Raychem invented many different varieties of heat shrinkable tubing made specifically for many different applications.  As an example, we have our WCSM - rated to 1000 volts.  But what about cases where 1000 volt resistance isn't needed?  Is there a more cost effective option?  Of course there is: MWTM rated to 600 volts. 

     The radiation cross linked PE backing is just a little thinner than the WCSM.  Thinner backing means less electrical resistivity.  Pretty simple. 

     The sealant coated MWTM (you know it is sealant coated when it has a -S in the nomenclature) is for use on insulation and jacket repair up to 600 volts or for general sealing and rejacketing of polymeric or elastomeric insulated cables up to 35kV.  MWTM has a 3:1 shrink ratio and an unlimited shelf life when stored under normal conditions.

     See the different sizes available above.  The first letters are of course the material type (MWTM).  The first number is the supplied ID of the shrink tubing.  The second number (after the /) is the size which the shrink sleeve tube will recover to.  The third number (1200) is the length of the tube as supplied (they can be cut down simply and easily). 

     So, the MWTM 85/25-1200-S is a tube rated to 600 volts, supplied with an ID of 85mm which will shrink down to a 25mm substrate - it is supplied in a 1200mm long tube (48") and is coated on the inside with a sealant adhesive. 

FCSM - Flame Retardant Heavy Wall Tubing

FCSM - for 1/C Low Voltage Power Cable (2000 Volts)

     Some applications require a flame retardant material in order to meet specifications for a project.  In those cases, FCSM can be the perfect option with it's tough, crosslinked polyolefin construction that provides mechanical strength and cut through resistance, equal to or surpassing the properties of low voltage cable jackets. 

     FCSM's 3 to 1 shrink ratio and unlimited shelf life when stored properly make it simple and easy to have on hand for emergency repairs and quick use.  FCSM can be used as jacket repair on cables up to 35kV.  It is available in both internally coated with a sealant (-S) and uncoated (/U) varieties. 

     The first chart lists all FCSM that are internally coated sizes.  Simply look for your cable sizes and your connector sizes and you will quickly zero in on the size you need.  The plant does require that standard box quantities are met which means you may have to purchase more tubes than you need at any given moment. 

     The bottom chart shows sizes for uncoated FCSM tubes (no sealant inside).  For questions and comments about FCSM, please contact us today:  steve@jsicoatings.com
    

CRSM - CRSM-CT

CRSM and CRSM-CT

     In the Raychem world, we have two products with very similar names:  CRSM and CRSM-CT.  What's up with that?  What do those letters stand for?  Why not use more dissimilar names because that gets kind of confusing?  I don't know any of those answers -- but I do know what CRSM and CRSM-CT stand for.

     CRSM stands for "Cable Repair Sleeve - metric" -- or alternatively:  "Cable Rejacketing Sleeve - metric".  The "CT" at the end of the CRSM-CT stands for "Cable Tap" splice.  That probably didn't help very much did it?  I think the primary difference between the two products is that the CRSM-CT (which is expected to seal between two cables as seen below) is manufactured with a significantly thicker adhesive layer.  That thicker adhesive is sufficient to fill all cracks and voids and even properly seal the area between two different cables that are running parallel to one another. 

Here you see how the adhesive thickness of the CRSM-CT is able to properly seal around two cables

     Both products utilize the same backing and the same rail and channel closure system.  In both cases, the product is rated for use at 1000 volts when in direct contact with the cable splice / the current.  When used simply as a jacket repair, however, the products are rated to 35kV.  Quite a difference depending on what the application is!  You certainly would NOT under any circumstances use this product to seal a high voltage splice.  That could be deadly.

     CRSM is available for use on cables #8 up through 2000 mcm.  CRSM-CT (on a compression connector) can be used on #8 up through 500 mcm cable.  When installing on a split connector, you (of course) need a sleeve large enough to wrap around two different cables; so in those situations you are looking at installing on connections using # through #2 cable size.