If you kink the tubing you can repair it by straightening out the kink and heating it with a heat gun or hair dryer until it reforms. Be sure to hold tubing  straight until it cools. Before performing this method, practice on a scrap.
    SPLICING; extra brass couplings should  be kept on hand in case the tubing is damaged. Be sure to cut the tubing square and insert it all the way into the fitting. If the coupling is put in concrete, sleeves are should be used to protect it from the concrete. Do not leave electrical tape directly on tubing. 

USING 1/2" BRASS COUPLING WITH BLACK CRIMP RING

INSERT COUPLING

CRIMP RING

INSERTS ARE REUSABLE

PEX TUBING

PLACE CRIMP RING OVER END OF TUBING,  PUSH INSERT INTO TUBING,
CRIMP RING WITH CRIMPING TOOL ONCE

COPPER COLORED CRIMP RING IS FOR POLYBUTYLENE NOT PEX

USING  QUEST COUPLINGS

CUT TUBE SQUARE AND SMOOTHLY

BUTT TUBE IN CENTER

TUBING

NUT

CONE

WASHER