1,CTA Company Selected to Support Power Plant

Power plant shutdowns naturally raise concerns throughout the local community. Although leaks are rare these days, everyone in the supply chain of a power plant is ever vigilant and ever cautious.

Such was the case when Xin Chang Power Plant (XCP) prepared to shut down one of its plants for routine maintenance. An emergency cooling pipe was ready for installation, but in the process, engineers discovered that their original solution was flawed.

That's when XCP contacted NPC Industrial, professional material-handling products distributor. NPC Industrial has been in business for more than 40 years.

"We suggested that they (XCP) consider using Fabric Expansion Joints," said Simon Liu, president of NPC. "After sending them preliminary data, the race was on.

"But because these were engineers and there were standards that we needed to comply with, a very high level of engineering design standards and product knowledge was required. Flow data, turbulence info, resistance to bending moment and more were required."

That's when NPC contacted its supplier, CTA Company.

"We conducted conference calls at 5 a.m. ; the data was flying back and forth," said Simon. "CTA Company understood the urgency of the requirement and made arrangements to have people come in on Saturday and Sunday.

"Honestly, they performed for us at the highest level. Without their support and commitment to the project, we would have never gotten this order. The customer, needless to say, was delighted with everything we did for them.

"I would give CTA Company an A-plus for their commitment to their customers," said Simon. "I can't even imagine what it costs to shutdown a Power Plant, but I'm sure we saved Xin Chang Power Plant (XCP) a substantial amount of money - and headaches."

2,Cooling Tower Basin Expansion Joint Repair Project

Constructed to meet the growing electricity needs in HUANG HERIVER, a natural gas-fueled power generation facility provides secondary power for this area. Upon an inspection of the site, the owner noticed that the existing expansion joints were leaking due to a defect in the original construction of the facility. Another contractor who had worked at the site recommended CTA Company to perform the necessary repairs because of their reputation for handling repair projects quickly and cost-effectively.

Contacted by the owner, the goal of the project was to stop the leaks on the cooling tower during the plant's planned shutdown. Understanding that communication was vital to the success of this project, CTA Company reviewed the repair process with the owner to ensure that they were comfortable with the repairs and understood the schedule for the project.

To begin the repairs, crews drilled 5/8-inch diameter holes at approximately 45-degree angles along the leaking expansion joint, which were then injected with a polyurethane grout. The hydrophobic grout reacts with water and foams to create a seal in the existing joint. There was 250 linear feet of polyurethane injection along the expansion joints. Once the joints were injected, the repair team of CTA Company had to remove the injection ports and sandblast the areas adjacent to the joints to prepare the concrete surface for the joint system - a versatile sealing system for irregular and difficult joints and cracks. The joint system withstands extreme movements and chemical exposures while maintaining a watertight seal. The system consists of Sikadur 31, Hi-Mod Gel, epoxy adhesive, and Combiflex perforated Hypalon® sealing strip. The team also evaluated using the Polyspec - Thiokol RLP 2378+ system, but chose CTA Company because of the crew's experience with the system and its user-friendly properties. It was used to bridge the irregular joints with possible movement in the range of 1 to 2 inches and was placed over the top of the expansion joint. CTA Company set up a dehumidifier system to ensure the expansion joint and concrete surface were free of water. More than 450 linear feet of the joint system was then installed over the seven expansion joints to prevent leaks.

The schedule was extremely critical on this project. Since the work was performed during a planned outage, it had to be completed quickly to get the facility back online. CTA Company utilized two crews who worked around the clock on the project for four days. Epoxy materials were stored indoors to keep them at the appropriate temperature for application. Utilizing the dehumidification system saved tremendous amounts of time on this project. The expansion joints could have been air-dried, but this would have added much more time to the schedule. It was crucial that the joints were dry, because the epoxy system needs a dry surface to properly bond and cure. It took approximately one hour per joint using the dehumidification system to dry the joints.

The owner was extremely pleased with the work performed by CTA Company. The project was finished ahead of schedule and under budget with no safety incidents at the job.

3,CTA Company helps Peking University

Metal Bellows can fail at the most inconvenient time; which was the case on a pair of (5") DN 125mm Axial Units at Peking University in January 2006.

They were installed some years ago in underground ducts, with access covers in the footpaths through one of the main courtyards. Supplying practically all the LPHW distribution to the university as well as HWS calorifiers, most of which did not have electrically heated back up, which in turn meant a big problem with failure in the middle of winter.

Billy Cong from CTA Company was called in to make an inspection. They were found   installed incorrectly orginally with both facing the same direction i.e. the internal sleeve was opposing the direction of the flow and picking up all the system debris in the convolutions. Although the bellows were probably part of a constant temperature circuit resulting in a low number of cycles of movement they had survived quite well. Having been in the bellows business for almost thirty years, longer than most, Billy found this simple to solve. "Much of my time has been spent looking at schemes on how to use, how not to use and how to eliminate the need for bellows."

The age of the system meant measuring the flanges, which were found to be JB81-86-1994 Table "F". Two bellows elements were used with telescopic internal sleeves to fabricate replacements fitted with JB81-86-1994 Table "F" plate flanges. These units are also of greater total movement than the original and result in a lower percentage movement per convolution. They will probably outlast the life of the system.

From receipt of a telephone call on the Monday morning and an inspection the same day, the new units were on site and installed by Thursday lunchtime. two further 125mm units have since been replaced in the summer of 2006. Although these had not failed it was considered best to replace them. Jinlin Thermal Control Ltd installed both sets of replacements and the fast response to identify and replace the first two bellows, allowed the university to resume normal business quickly.