Tapered Tube Plugs – Not as Simple as it Seems

Tapered Tube Plug

 

 

 

 

 

 

 

Used during repairs and outages, this simple looking device becomes a necessity. The Tube Plug is hammered or welded into the open section of pipes in boilers and heat exchangers. They plug the end of the pipe to either stop the flow of steam or coolant. If the plug’s seal is not tight the coolant can seep into the material and contaminate it.

 

Heat Exchanger End *
Heat Exchanger Side *

 

 

 

 

 

 

 

 

What makes this seemingly basic item so important are a few factors. First, its fit must be right. Sure they are tapered, but they must fit without damaging the existing pipe or sliding too far in. Also, the material specifications for Tube Plugs can vary greatly. While some plugs can be made out a carbon steel like 1018, other plugs must match the existing pipe section (i.e. A350 with more carbon content) or even stainless steel, nickle or other metals. If the wrong type of metal is used, it could lead to corrosion, rust, leaks or a possible reaction with existing materials in the system.

 

Tube Plug in CNC Lathe

 

 

 

 

 

 

 

 

Even the machining isn’t always as simple as it may seem. Bar stock in not always available in a size close to what the job requires or the material type needed is only available as plate. In that case, a plug larger than the finished size would be cut from the plate and then turned turn by hand on a lathe. Time consuming, yes, but necessary for a professional fit.

 

Plug cut from plate
Sample Heat Doc

 

 

 

 

 

 

 

 

 

 

At Riggs Machine & Fabricating, we not only have the experience, but we ask the questions to make sure the job is done right, the first time. Don’t trust those supposed simple jobs to just any shop. Call Riggs first for the dependability and quality your facility demands.

 

Set of Tube Plugs

 

 

 

 

 

 

 

*(Morton, John, 2 Electrolyte Heat Exchanger Tube Bundles in the 8×6 Foot Wind Tunnel, 1975) – http://catalog.archives.gov

Industrial Classroom Training Aids

If you ever wondered where the custom training equipment in industrial classrooms come from, then look no further than Riggs Machine.

 

 

 

 

 

 

 

 

At Riggs we can create custom pieces from scratch, like this “oil flinger” demonstration unit. Shown from conception, with 3D renders, to the final unit in the classroom.

3D Oil Render Test
Oil Flinger 3D Render

 

 

 

 

 

 

 

 

And we also often disassemble, create “cut-away” sections, sandblast, paint and reassemble actual pieces of equipment to be used in working classrooms. These units are used for hands-on training before students hit the field. Much better than a video or book based lecture.

FinTube Assembly – Ready for Class
Custom Cut-Aways

 

 

 

 

 

 

 

 

 

 

Some of these jobs can be more time and labor intensive than actual repairs! But we don’t mind. We’re proud to be part of the team who help educate the next generation who will be keeping our refineries, steel mills and factories running.

Pump Cut Away in Process
Pump Lid – Painting Detail

Explosion Proof Hatch – Pyrite Ducts

Here are some newly machined explosion-proof hatches for pyrite ducts.

In preparing coal for energy production, pyrite, a sulfide that contributes to air pollution and acid rain, is removed before burning. The separated pyrite is forced through ducts to waiting hoppers using high pressure fans. These ducts have negative pressure in them. If a chunk of pyrite gets stuck in a hopper then unit has to be shut down and the duct removed from the unit to be cleaned.

Photo by James St. John / CC by
Sphalerite-Pyrite

With the addition of these hatches, if a chunk of pyrite gets stuck in the hopper, it is only a temporary shut down while the hatch is opened and the material is washed out. Once the hatch is sealed, the unit is quickly brought back on-line. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

These hatches have also been used as inspection doors on gearboxes, giving quick access to the internals for routine maintenance or adjustments. The locking tab on the hatches also helps keep the unit secure.

 

A Phonographic Finish!

No, not what is used when a race is too close to call (that’s a photo finish). But a machined finish added to the raised face on a flange to give an extra level of security to prevent leaks and maintain effective seals.

Spacer Flange w-Phonographic Finish

The Phonographic Finish is actually a serrated finish, either concentric or spiral (much like the grooves on a record), that will grip the gasket between pipe sections firmly.

Phonographic Finish – Close Up

These finishes are typically added on a lathe to specifications set either by the company ordering the flange, the manufacturer or ASME B16.5 guidelines. Below is a render of the completed flange with bolt holes. I would have included a photo of the actual completed unit, but as soon as it was finished, it was rushed to the job site! But that’s why we’re here. Everyone knows who to call when a custom part is needed in a hurry.

Spacer Flange – Render

Stripped Industrial Bolts

Industrial Fan Housing

Stripped Industrial Bolt

 

 

 

 

 

 

 

Ever strip a bolt? Frustrating! How about a 22″ long x 3 3/4″ wide heat-treated bolt on an industrial fan housing? Nightmare!

Fan Housing on the VMC
Fan Housing on the boring mill
Drilling Out a Bolt
Drilling Out a Bolt

 

 

 

 

 

 

 

 

 

 

 

Not many shops have a horizontal boring mill large enough to handle components this size. But it’s just another day at Riggs Machine.

Industrial Bolt Cut
Industrial Bolt Cut
Catfish
Catfish

 

 

 

 

 

Next time you’re staring down the wrong end of a broken or stripped bolt the size of a catfish, you’ll know who to call.

 

Post Ash Loader Project

Post Ash Loader Project

post ash loader

We Love Big Projects!
One of the most exciting projects we’ve worked on has been the Goodman Industries Radio Controlled Pot Ash Loader.

From design, to welding, electrical, hydraulics and then field testing.

loader blades   loader tracks   loader side controls

Tested & Trusted
Riggs products are used in all conditions, in all type of facilities and in many different environments.


Still wondering if Riggs can handle your job?

miner in action

Roll Turning

precision cut roll

The Heart of the Steel Plant – the Rolls!
Flat rolls, grooved rolls or custom cuts, if the rolls aren’t to spec, the final product won’t be either.
Not only do bad rolls produce bad products, they can be dangerous to your facility.

roll dwg

A Pioneer in CNC Roll Turning
Riggs was one of the first shops to use CNC lathes to dress passes in rolls.
This is far superior to the old plunge cutting method. CNC pass cutting gives exacting tolerances and an exceptional finish.

cnc roll turning  cnc roll cutter

Roll Dressing
Work roll turning, with or without the chocks. Another convenience Riggs offers. Local pickup and delivery is also available.

finished roll set