Yes, that can work. But it will be a better seal if you had the same size nipple with a barb. The barb on the nipple helps it from blowing off under pressure. I recommend trying to find one with a barb, and the pipe as a last resort (if it is the same size as the nipple on the water pump). It's easier to find a bypass hose with a consistant diameter than try to run the one with two different sizes to match two different size nipples.