CE Series Plastic Pipe Cap CE Series plastic pipe caps protect against damage and debris. CE-309 through CE-326 feature an NPT taper; all others have straight walls. Material: Low-Density Polyethylene Color: See Chart B A EPN-240 Series Closed-End Recessed Caps EPN-240 Series closed-end recessed caps accommodate crane hooks for ease of mobility, loading and unloading. Material: Linear Low-Density Polyethylene Color: Black C A 334 * For other material and color options, contact customer service. B