Flexible, light and form-fitting, this tank uses a PVC bladder inside a tough, abrasion-resistant nylon outer envelope.” Maintenance is easy because the inner bladder can be removed for cleaning and inspection. The bladder is slightly oversized so pressure is exerted on its nylon shell rather than on the heat-welded seams. 1 1/2" 90 fill and 1/2" straight outlet fittings ready to install.