Properly bidding on pipe welding work requires you to consider as many elements of the job as you can anticipate.These factors include: the size of the job, the job specifications, the labor required, the materials purchase plan, owner contingencies, the time frame and a universe of minor details. No bid can take every element into account, but the more factors you can account for, the less chance there is of a disagreement when it is time for you to get paid. The elemental formula for bidding a pipe job is: fuel costs + material costs + labor + profit margin = bid.
Ask the contractor what substance the pipe will be moving. Then you know the required welding specifications. For example: If the pipe is water pipe for artificial snow-making and you have experience welding water pipes, the job is for you -- if the terms of the agreement are right. On the other hand, maybe the pipe job requires someone with an open-root pipe welding certification. If you do not have a G6 certification and you can't hire someone to do that portion of the job for you, bidding on the job is a waste of your time.
Ask the contractor for a copy of the job's plans. Try not to get yourself in a situation where you only have an estimation of the size of the job. If you have the plans, you can add up the footage yourself. The most important thing you need to know about every pipe job is the size. Maybe the job is too small for you and you can make more profit focusing your time elsewhere. Or maybe the job is too big and you do not have the resources to complete it on time. Maybe the job is big but you can hire some help to give you a hand. You can't answer any of these questions, or make any decisions, if you do not know exactly how big the job is.
Figure out the time frame. This is not just a matter of how much time you have to complete the pipe work. You must also find out what the time obstacles are. Are there other crews working around you that might impede your work? Idle time costs you money. Account for it in your bid. Are there crews working behind you that will be waiting for you to complete your work before they can begin theirs? Will they be hurrying your work? If you are hurried, you will need more laborers. That is a cost. Account for it in your bid.
Get a master list of given materials -- materials that will be purchased for you. Know what you are going to be responsible for purchasing before completing your bid. If you have to pay for the pipe, the price of your bid is going to be significantly higher than for a job where the contractor is purchasing the pipe and all you have to do is weld it and provide the machines and labor.
Account for fuel costs. If the job location requires traveling a long distance, the cost of fuel can be substantial. Do not make the mistake of not accounting for fuel costs.