Had a salesman come in the other day and sell me these torch tips called "the hook" said they would heat the pipe evenly around the pipe. Tried the large one but keeps blowing the flame out on a 7/8 line. Not sure if I am doing it correctly. oxy @ 25 acet @ 7-8. Not all the orfices blow out but seems to be the end one, 4 on the lg. one and three on the samller one. Anyone else use this and how does it work for you?