We are not a pediatric hospital but once in a while we have 'special' pediatric heart week cases where these specialists come and fix PDA's an other heart deformities. These are scheduled procedures so we usually have an O neg, cmv neg blood unit with attached 'Pedi Paks or transfer packs'. 

My question is if we aliquot a unit off the primary bag and use hand sealer clips (we do not have a heat sealer) to split the unit, does that make it an open-system split?? We cut the tubing with scissors cleansed with alcohol. That would make our expiration 24 hours if so. I've looked on the web and a closed system is always defined as "using a sterile connecting device". If we split a unit without the transfer packs attached to it then it is definitely an open split and the expiration is 24 hours however I'm not sure with the attached transfer packs where we are not spiking the primary bag to aliquot off of it but we also do not have it heat sealed, just crimped with  a minimum of 3 clips

If the parent blood unit comes to you with the pedi bags attached, and you are just sealing them off (whether heat sealer or hand sealer clips) - AS LONG AS THERE IS NO VENTING AND YOUR SEALS ARE ALL TIGHT - you would retain the parent outdate. 

I imagine the pedi bags are connected to the parent with a sterile connecting device. 

So you're good to go!

The question is how the pedi pack/ transfer pack is attached.  Not how it is removed.  If it is attached via sterile technique so as to not jeopardize the sterility of the product, it should retain it's original outdate.
When you remove it, you just need to ensure that it is a "permanent seal" not just a clamp with can accidentally open.  Those grommets are generally considered a "permanent seal".

Yes the pedi bags are connected to the parent with a sterile connecting device. And no it is not just a clamp but an aluminum 'clip' in which you, I guess 'crush' or 'crimp' down onto the tubing which cannot be removed without a struggle. Thank you for the replies, very helpful.