AB „Vilniaus šilumos tinklai“

Vilnius, Lietuva

2022

Installation of a double-suction 315kW power network pump

In 2021, UAB “Gandras energoefektas” won the tender for the installation of a network pump at the Vingrių pumping station in Vilnius.

Basic customer requirements:

• Design and install a new pump instead of the existing TS-3 pump. The capacity of the new pump must be 1200 m³/h, head H=64m, T=120° The new pump must be operated with the existing frequency controller, from the mains 0.4kV.
• Replace the pipeline connecting the new pump up to the shutoff valves (inclusive)
• Shut-off valves: manual butterfly type valves DN400 with triple eccentricity (metal to metal)
• Mechanical filter with a mesh size of not more than 5 mm.
• Vibration of the pump must not exceed 1.4 mm/s (with an allowable rate of 2.3 mm/s)

Project implementation:

The design and construction was carried out in accordance with the requirements of tender conditions. The scope of supply included a pump, concentric rubber expansion joints (to compensate for thermal deformations of pipelines at T=120°C), an angular (inlet and outlet at 90°) strainer, two butterfly valves, a check valve and pipelines with thermal insulation.

Commissioning:

During commissioning, it was determined that the pump was running with high vibration. This is due to the fact that he goes beyond his work schedule. Since the customer did not have a metering device at the facility, it was necessary to determine the required performance of the pump and its pressure by opening and measuring the existing pump, manufactured in 1972.

UAB “Gandras energoefektas” came to the conclusion that for the correct operation of the system, a pump with a capacity of 2000 m3/h and a head of 30 m is required. Also, at the suction it is necessary to install a filter of a different type and diameter DN400, replace the butterfly valve DN400 with a full bore ball valve and replace the check valve DN300 with DN400. Customer agreed to reduce the temperature requirements from 120°C to 60°C, which eliminated the need for expansion joints.

During design and construction, the customer consulted with other pump manufacturers, who stated that it would not be possible to turn on the pump at full capacity until the pipeline was replaced with a diameter of DN600 and straight sections of at least 5 diameters in front of the pump were organized (due to lack of space on site, UAB "Gandras energoefektas" designed steeply curved elbows upstream and downstream of the pump).

Problems in the construction of a new pump:

• Due to lack of space, a DN400 full bore valve had to be cut into an old pipe that complies with the GOST standard, but meet the requirements of CE and PED.
• The filter should be designed to be as compact as possible (pipe size DN400) and create minimal turbulence and flow resistance.
• The design of the pump must be very strong in order to be able to work with steep bends before and after the pump without increased vibration.

Results:

When the pump was turned on, it was found that the engineers of UAB “Gandras energoefektas” were completely right.

• The pump works at an operating point of 2000 m3 / h and 27 m. The vibration of the pump is two times lower than the norm (fully meets the requirements of the customer - do not exceed 1.4 mm / s at a rate of 2.3 mm / s).
• At a capacity of 2000 m3/h, the differential pressure in the filter is 0.2 bar.

Conclusions:

After installation works on pumping station were finished UAB “Gandras energoefektas” became a “happy owner” of the following equipment:

• double suction pump, capacity 1200 m³/h, head H=64m (with mechanical seals designed for operation at 120°С)
• butterfly valve DN400 PN25 with triple eccentricity (metal to metal)
• check valve DN300 PN16
• mechanical corner filter DN350 PN16
• concentric rubber expansion joints DN250/300 PN16 and DN300/350 PN16

If the contractor has the necessary engineering experience and connections with manufacturers, then this can allow the customer not only to get out of a difficult situation, but also save a huge amount of money. The example of this project shows that UAB “Gandras energoefektas” is exactly this type contractor.

Important request to customers:

If you do not know the exact parameters of your system or have doubts about them, indicate in the tender conditions that the contractor must determine these parameters himself before submitting the tender.

TS-3 pump before reconstruction:

TS-3 pump after the first stage of reconstruction:

TS-3 pump after the second stage of reconstruction: