25-09-2012

Non-standard equipment has been manufactured at the Bugulma mechanical plant

Bugulma Mechanical Plant (BMZ), part of the OAO TATNEFT structure, has manufactured non-standard equipment: a gas separation unit (3S separation). This large-sized equipment, making 5 cargo packages on railway platforms, has gone to Uzbekistan, where it will be put into operation.

The gas separation unit, manufactured by BMZ, is designed for intensive natural gas drying and extraction of target components installed at the centralized gas treatment installation, where low-temperature separation is carried out with application of a throttle valve. Gas is cooled at the centralized gas treatment installation in shell and tube heat exchangers with cold gas fed to the return channel through the throttle valve. The manufactured unit will be installed at the centralized gas treatment installation replacing the throttle. Its implementation at the gas fields belongs to the category of energy and resource saving technologies and allows not only reducing capital and operating costs of construction and operation of gas fields, but also essentially improving the reliability and environmental safety of the processes of collection and in-field treatment of natural gas.

The gas separation unit consists of a heat exchanger, separator and two 3S-separators. Four components fabricating shops and an assembly shop were involved in the unit manufacturing. The unit throughput is 115 thousand m3/h at 7.5 MPa input pressure. This high pressure requires a large wall thickness of the vessels and large flange disks. Thus, the heat exchanger wall thickness is 32 mm with the flange disks' thickness of 150 mm. The weight of the heat exchanger is 18,500 kilograms.

The internals of 3S separator, which is part of the unit, are made of stainless steel. The total length of the internals amounts to 1800 mm. The parts are high precision machined and fabricated at the machining tool repair shop of BMZ.

The works performance was complicated by the larger size of the flanges applied. The stepwise assembly of individual components was carried out at the assembly shop. The unit is an oversized product; therefore the assembly was performed on two channel beam structures. The unit height is 6,100 mm, which resulted in the need to work at height using hoist units and special mobile carts for the installation, assembly and disassembly of the unit.

Due to the stringent requirements with regard to the chemical composition of the medium, in which the unit is supposed to operate all the incoming pipes and vessels were heat treated. This resulted in a two-stage assembly and disassembly of the entire unit. The heat exchanger vessel, which is part of the unit, was assembled at the section of the heat exchange equipment assembly, while the 3S-separator and the separator were assembled at the area of tanks and vessels equipment assembly.

It is a good experience for the Bugulma Mechanical Plant to manufacture this type of equipment. The design changes agreed with the customer were introduced into the engineering project in the course of the works. Additional flange connectors were introduced, the frame with 3S-separators was raised and bolted connections were introduced from top to bottom of the frame.