In the 90s, you could acquire max-level skills every 14 days.

Chapter 131 Two people welding double-layer sleeves

Li Guilan left home early in the morning.

She said she had found out that the list of recipients for the welfare housing would be announced next week, and if she wanted a spot, she should go to the section chief as soon as possible. She pedaled her bicycle quickly towards the factory.

Zhang Yong wasn't idle either.

When the Jialing 125 roared to the entrance of the Tongxian Dongsheng Coal Mine, Fang Qiming's jeep was already parked next to the guardhouse.

The truck bed contained two sections of 16Mn steel pipes and a box of high-temperature resistant sealant, all tightly bound together with hemp rope.

Qian Zhiyuan jumped out of the car, still holding a stack of printed calculation sheets in his hands.

"Zhang Yong! Let's go, straight to the workshop!"

Fang Qiming stood at the entrance of the boiler workshop, his expression not looking good.

Zhang Yong stepped into the workshop, and a stench of rust mixed with coal dust hit him. The incandescent light overhead swayed, its light shining on the dismantled pipe sections.

The main steam pipe elbow of Boiler No. 1 has been removed and placed on two sleepers.

Zhang Yong squatted down and glanced at the cross-section, his heart skipped a beat.

The inner wall was riddled with corrosion pits, one after another, the bottom of which was black and purple. The deepest part could be pierced directly with a probe. Qian Zhiyuan counted down the depths: "The thinnest part is 6.8 millimeters, and the corrosion depth is 5.2 millimeters."

It's not the previously estimated 3.7.

"It's more serious than I thought." Fang Qiming took off his glasses and wiped them, his tone heavy. "If this bend continues for another winter, once the peak pressure hits, there's a 40% chance the pipe will burst."

Meng Qingshan's face turned ashen; he felt both relieved and frightened.

Thankfully, someone came to check on me, otherwise I would have been in real trouble.

Old Zhou, the old furnace worker, glanced at the cross-section and was so frightened that his hands trembled.

"This—we didn't understand this before. We only learned in the last few years that we need to treat the water, otherwise it will corrode the pipes, or else—"

"Factory manager, let's replace it with a new bend!"

Fang Qiming turned to Qian Zhiyuan and asked, "What's the price of imported elbows?"

Qian Zhiyuan flipped through his notebook. "The agent in Harbin quoted 8,000 yuan, with a delivery time of 50 days. If it's shipped by sea, it will add another two weeks."

"More than two months?" Meng Qingshan's voice rose. "Heating will be on in another month and a half!"

The workshop fell silent. Eight thousand yuan, fifty days.

Meng Qingshan clenched his fists. How much profit did the entire factory make in a year?

Winter will arrive in two months, and the three residential areas are waiting for heating to be turned on.

If the supply can't keep up this winter, not only will we be criticized, but we also won't make any money this year.

No one spoke in the workshop. The incandescent light overhead flickered, and shadows swayed on the concrete floor.

Zhang Yong squatted down in front of the broken bend, staring at the shocking corrosion pit, and patted the rust powder off his body.

Then he took a piece of chalk out of his pocket and started drawing on the ground.

First, draw the cross-section of the elbow and mark the residual wall thickness of 6.8 mm.

Then, a slightly larger circle was drawn on the outside, representing the cross-section of the sleeve, which is two sizes larger in diameter. The gap between the two layers was marked with a number: 3 millimeters.

"Teacher Fang, please take a look."

Fang Qiming walked over, squatted down, and looked at the sketch on the ground.

"Let's stick to the safe approach, double-layered sheathing." Zhang Yong pointed to the outer layer with chalk.

"16Mn steel, 8mm wall thickness, one size larger than the original elbow. It is fitted on the outside, filled with high-temperature resistant sealant in the middle, and fixed with a circumferential weld at each end, and then reinforced with another weld in the middle."

He wrote a few numbers next to the sketch.

"With the original residual wall thickness, the equivalent pressure bearing capacity is equivalent to a single-layer pipe of more than 14 mm, which is absolutely safe."

Fang Qiming stared at the sketch, his finger tracing the lines of the sleeve cross-section.

"There's no mechanical problem. The coefficients of thermal expansion are the same for both layers, so there won't be any delamination stress." He nodded, then looked up at Zhang Yong.

"However, due to limited on-site conditions and the need for purely manual welding, it is difficult to guarantee the quality of the welds."

"It's not convenient for us to move the pipe, since it's already very fragile."

Zhang Yong smiled.

"Teacher, you forgot, we have an experienced pipe welder here who can give it a try."

Then he looked at Meng Qingshan, who looked anxious, and saw him hesitate for half a second before pointing to himself: "Me?"

Fang Qiming's eyes lit up. He had heard Zhang Yong say that the pipe had cracked before, and it was this deputy factory director who personally welded it back together.

"Okay, but I can only weld large pipes; I sometimes don't do a good job with small places."

Zhang Yong didn't say anything more and squatted back down in front of the bend.

"I understand your concerns." Zhang Yong stepped forward and straightened the temporarily fixed sleeve. "You can try the initial weld first to get a general idea of ​​the position. I'll finish the details and critical welds."

Zhang Yong knew that welding in auto repair was a delicate job, and he was better at it in tight spaces.

However, when it comes to welding large-diameter pipes, Director Meng, who has been stationed at the factory for many years and has experience in emergency repairs of main pipelines, has more experience.

Factory Director Meng looked like he'd been forced into this situation, so he could only pull down his mask and turn on the welding machine.

After Meng Qingshan finished the initial welding process, he stepped aside, and Zhang Yong took over the welding torch.

The moment the welding torch was ignited, a blue and white arc of light exploded in the workshop.

Everyone took a step back.

Zhang Yong's wrist sank down, and the welding wire stuck to the steel joint.

In my mind, the system panel was running silently.

[Automotive Repair Lv.5 Effective: Torque Sensing & Welding Current Feedback—Wire Feed Speed ​​1.2m/min, Current 135A, Arc Length 2mm, Stable]

His hands were incredibly steady.

The welding wire advances at a constant speed on the joint, the molten pool is neither too big nor too small, and the start and end of each section are seamlessly connected.

Qian Zhiyuan stood three meters away, watching silently, holding the ultrasonic flaw detector in his hand.

It took more than twenty minutes to finally finish welding.

The arc light went out.

Zhang Yong took off his mask, his forehead covered in sweat mixed with rust powder, streaked with gray and black.

"Take the test."

Qian Zhiyuan took the flaw detector and applied it.

The probe slowly slid along the first weld seam, and the waveform on the screen was as smooth as a straight line.

He walked around twice before turning off the flaw detector, then looked up at everyone.

"Yes, it's fine, no defects."

The workshop fell silent again.

Fang Qiming stepped forward and touched the surface of the weld with his fingers. It was uniform, full, and the fish-scale pattern was clear.

He turned around to face the four graduate students behind him.

"Come here, everyone. Take a look at the welding details. This is a ready-made example, so you'll have a better understanding of welding techniques in the future."

77

Meng Qingshan started counting the money on his fingers.

"Casing steel — 120?"

"One hundred and twenty, sealant eighty, welding material thirty." Zhang Yong put the welding torch back into the toolbox. "Two hundred and thirty in total."

"It can last for a few years, at least until next summer when you can replace the pipes."

"Let's take another look at how to install the nozzle."

Meng Qingshan's mouth was open, and he couldn't close it for a long time.

Two hundred and thirty yuan replaced an imported part worth eight thousand yuan.

Before he could even react, a worker poked his head out and said, "Factory manager, let's eat first."

"Sister Wang from the cafeteria just said that someone delivered vegetables to our cafeteria."

"There are still several cases of grain liquor! I'll have to ask you to go to the canteen to check on them."