 Instead, pipe and fittings with plain (non-belled) connections are butted against each other, and clamped with special rubber sleeve (or "no-hub") fittings.The rubber sleeves are typically secured with stainless steel worm drive clamping bands, which compress the rubber to make a tight seal around the pipes and fittings.These pipe clamps are similar to hose clamps, but are heavier-duty and ideally are made completely of stainless steel (including the screw) to provide maximum service life.