H/HH Fin Tube
Split square fins welded in pairs, leaving a straight ash lane along the tube
What H/HH Fin Tube Is
An H type fin tube carries flat square fins welded on in halves, so a gap runs the length of the tube between each pair - the shape that gives the type its name.
That gap is an ash lane. Fly ash falls through instead of bridging between fins, which is why H type banks stay cleanable in coal and biomass flue gas.
HH doubles the arrangement for heavier duty. Fanbang produces both on two dedicated H and HH production lines.
Why Engineers Specify It
Ash falls through instead of bridging
The split between fin halves leaves a clear vertical lane down the tube.
Thick fins survive soot blowing
Fin thickness from 1.5 mm to 4.0 mm withstands mechanical and steam cleaning cycles.
Wide pitch for dirty gas
Fin pitch from 9.0 mm to 30.0 mm opens the bank for the dirtiest streams.
Large fins for low grade heat
Fin height up to 45.0 mm recovers heat from gas that a short fin would leave in the stack.
Where It Is Used
- Economizers
- Heat exchangers
- Marine boilers
Buyers Who Come to Us for This Tube
Coal and biomass boiler builders
Ash-laden flue gas where fin fouling drives outage frequency.
Marine boiler manufacturers
Compact heat recovery banks that must stay cleanable at sea.
Economizer retrofit contractors
Replacing spiral banks that blocked with ash.
What Goes Wrong Without It
Ash bridging between fins
Split square fins leave a straight lane so deposits drop out of the bank.
Fin erosion from soot blowers
Fins up to 4.0 mm thick take repeated cleaning without thinning to failure.
Frequent outages to clean the economizer
Wide fin pitch keeps gas side pressure drop stable for longer between cleans.
H/HH Fin Tube Dimensions
These are the ranges our production lines run. Sizes outside them are quoted case by case rather than assumed.
| Item | Specification |
|---|---|
| Base tube diameter | 25 mm - 73 mm |
| Base tube wall thickness | 3.0 mm - 6.0 mm |
| Fin thickness | 1.5 mm - 4.0 mm |
| Fin pitch | 9.0 mm - 30.0 mm |
| Fin height | 15.0 mm - 45.0 mm |
Materials
| Component | Materials available |
|---|---|
| Base tube | Stainless steel, carbon steel, alloy steel, nickel |
| Fin plate | Carbon steel, stainless steel, alloy steel |
How It Is Made
H/HH Fin Tube on the Shop Floor
Inspection and Certification
Every tube passes eddy current and hydrostatic testing, with tensile, flattening, flaring, hardness and chemical analysis carried out on our own equipment. Fin pitch, fin height and finned length are verified as dimensional items in their own right.
The company holds ISO 9001:2015, CE certificate, Production licence for pressure pipe.
What Can Be Changed
- Base tube material and wall thickness within the range above
- Fin material, fin pitch and fin height to the bundle design
- Finned length and bare end length for the tubesheet joint
- Marking, packing and certificate scope for the destination market
Compared With the Alternatives
H type gives less surface per metre than a spiral fin but keeps working in ash-laden gas where a spiral bank blinds over. Against stud fins, H type holds more surface area; stud tubes stay cleaner still in the very dirtiest furnace duty.
Use Guide
- Pick fin pitch from the dust loading of the flue gas, then check gas side pressure drop - not the other way round.
- Where soot blowers are installed, state their type so fin thickness can be set for the erosion they cause.
- HH is used where the duty needs a second fin pair per pitch; confirm the bank depth before choosing it.
H/HH Fin Tube FAQ
What makes H type suitable for dirty flue gas?
The fin is welded on as two halves with a gap between them, so ash falls through the lane instead of bridging across the fin.
What is the difference between H and HH?
HH uses a doubled fin arrangement for heavier heat recovery duty in the same bank geometry.
What base tube sizes are available?
25 mm to 73 mm outside diameter with 3.0 mm to 6.0 mm wall thickness.
How tall can the fins be?
15.0 mm to 45.0 mm, with fin thickness from 1.5 mm to 4.0 mm.
Often Compared With
Spiral Fin Tube
Continuously welded helical fin for boiler, economizer and flue gas duty
Base tube diameter: 15 mm - 70 mm · Base tube wall thickness: 2.0 mm - 15.0 mm
Stud Fin Tube
Individually welded studs for the dirtiest furnace and process heater duty
Base tube diameter: 38 mm - 273 mm · Base tube wall thickness: 3.5 mm - 10.0 mm
Longitudinal Fin Tube
Straight fins welded along the tube axis for viscous fluids and low velocity gas
Base tube diameter: 12 mm - 273 mm · Base tube wall thickness: 2.11 mm - 25.4 mmIndustries using this tube
Related reading
Quote H/HH Fin Tube From Your Drawing
Send base tube size, wall thickness, fin geometry, material and length. You get a quotation against the drawing, not a catalogue page.
[email protected] · Tel 0086 512 58392615 · Monday to Saturday, 08:30 - 17:30 China Standard Time (GMT+8)