Hiring The Services For Testing And Certification Of Lifting Machines, Lifting Tackles Like Hot/Eot Cranes, Hoist, Chain Pulley Blocks, D-Shackles, Slings, And Hydrostatic Testing As Well As 6 Monthly External & Internal Testing With Certification Of Air Vessels, Prvs, & Trvs At All The Installations Of Oil India Ltd In The State Of West Bengal ( Ps-7, Madarihat & Ps-8, Sonapur ) And Bihar ( Ps-10 Barauni ) For A Period Of 4 Years