Bespoke Dye Penetrant Inspection (DPI) EquipmentJohnson & Allen is an experienced manufacturer of NDT systems and have designed and manufactured Penetrant Inspection Lines for over three decades. In that time have supplied bespoke systems to market sectors including aerospace, automotive, rail, oil and gas, military and general engineering; With prominent customers including the Vector Aerospace, BAE Systems and Rolls Royce.Johnson & Allen Penetrant Inspection lines are ideal for testing large volumes of components, environments where dye penetrant processes are used regularly and in teaching environments.