Acid Corrosion Forum
Focus: These forums are provided as a service to our guests & customers who have industrial corrosion issues dealing with strong acids in chemical plants, mining operations, energy, pharmaceutical processing, laboratory testing etc.
Moderator: Dr. Hira Ahluwalia is an independent materials expert who has run Materials Selection Resources for over 30 years and has extensive experience in materials selection, corrosion testing and failure analysis. With a focus in the chemical processing and pharmaceutical industries, Dr. Ahluwalia provides his unbiased expert opinion to forum guests having industrial corrosion inquiries. For more detailed consulting, Dr. Ahluwalia (see his background) can be contacted at hira@doctormetals.com or www.doctormetals.com.
Categories
- Halogenated Acids
HCl, HF, HBr & HI
5 topics
- H2SO4
H2SO4
7 topics
- Organic Acids
Acetic Acid & Formic Acids
2 topics
- Other Corrosive Media
Mixed acids, molten metals, supercritical conditions, ultra-high purity, etc.
4 topics
- Tantalum Coatings
Discussion of tantalum coatings for various corrosive applications
4 topics
Recent Topics
Acid Resistant Ball Valves, OP confirmation
msolano · · No replies
Is possible to connect a open position confirmation at Acid Resistant Ball Valves? and if is possible which model is available?
Heat Exchangers -HF / Piranha Acid
Michael · · 1 reply
Hello, Im interested in the Ultramet CPT technology for two different heat exchanger services. I need one heat excahnger to cool HF ( 40% hydroflouric acid and nitric acid). The other heat exchanger I need for a piranha…
Tantalum Fittings
Michael · · 1 reply
Hello, We need tantalum fittings in our system and some times it is not practical to get parts loose lined with tantalum either due to the size or geometry of the part. Do you supply ‘off the shelf’ common process…
Valves for HCl
James Sullivan · · 1 reply
Hello, My application deals with hot hydrochloric acid (HCl) at about 27% and 50C. Typically we use Hastelloy ball valves and Hastelloy plug valves but after a few months it is impossible to get leak tight shutoff or…
Sulfuric Acid Heat Exchangers
James Sullivan · · 1 reply
Hello I have a sulfuric acid (H2SO4) heat exchanger application and I wanted to know the benefits of the tantalum surfaces over a PTFE or Hastelloy C276 (These are the two other materials we are considering). My…
Valves for Strong Acids
James Sullivan · · 1 reply
Hello, I have an application that requires acid resistant ball valves in a solution that is mostly sulfuric acid. We have had mild success with Hastelloy valves but after a few months it is impossible to get leak tight…
PTFE Lined Thermowells
JohnM · · 1 reply
Hi, I have an application that I am wondering if the Ultra-Metal tantalum surfaces is a good solution for. I have several thermowells in a very corrosive HCl environment (80C, 20%). From a corrosion point of view, it…
Pump Impellers for HCl
John Silva · · 1 reply
Hi, I have an applications where pump impellers are getting corroded badly from HCl in a mining type application. There are no solids or particulates in the stream when the HCl is in contact with the pump. We have tried…
Tantalum Corrosion Resistance to HCl
David Hessler · · 1 reply
Hello, I have an application that utilizes HCl at a concentration of about 32% and at 120C. I have tried Hastelloy C276 but the corrosion rate is too fast and polymer liners are not possible as the HCl vapors see to…
Tantalum Thickness for H2SO4
Ben Davis · · 1 reply
Hello, My application utilizes a range of H2SO4 from 99% down to 15% at about 120C. I know most materials like Zirconium and Hastelloy generally cannot survive under those various conditions and my understanding is that…
Tantalum Coated Thermowells
Pete121 · · 1 reply
Hi, I have an issue with thermowells in a very corrosive acid steel pickling environment. The main issue I have aside for the extreme corrosive nature of the picking acid is that I need the thermowells to be very…
Thickness Requirements
Frank · · 1 reply
Hi, We are considering to use the Ultramet tantalum coatings on our valve components but was wondering how thick the surface needs to be to account for the corrosion rate of the media. We have various applications in…
Acetic & Mixed Acids
Kent · · 1 reply
Hey Guys, I have no experience with tantalum but heard its extremely corrosion resistant and might work in my application so I am looking for some advice. My application is primarily acetic acid with a variety of other…
HCl and Sodium Cyanide Solution
JohnH · · 1 reply
Hi, I know from my experience with tantalum that it will be fine in the HCl acid environment but during our process the tantalum will be exposed to a sodium cyanide solution which creates a basic environment that could…
Sulfuric Acid Agitator
JohnH · · 1 reply
We are designing an agitator for a sulfuric acid process containing 75-80% sulfuric acid near the boiling point of 160-170C. We are interested in Ultramet CPT's tantalum surface but wanted to understand the corrosion…
Range of Sulfuric Acid Tantalum is Good For?
JohnH · · 1 reply
Hi, My application uses range of sulfuric acid (H2SO4) from 98% to about 10% at temperature less than 200F. Will your tantalum diffusion surfaces be corrosion resistant in that range of conditions?
Dissimilar Metals
ehinshaw · · 1 reply
Hey Ultramet CPT, I was working with a rupture disc company the other day for a mixed acid environment where they had recommended to use a nickel alloy in combination with a Ta burst disc. I am concerned about the…
Nitric Acid Pump Impeller Corrosion
JohnH · · 1 reply
Hi, We are pumping nitric acid right now using a Hastelloy C276 impeller that is getting eaten up pretty quickly. We believe we are having not only corrosion issues but some cavitation due to the corrosion pattern. Any…
H2SO4 with Ferric Ion Contamination
Dan · · 1 reply
Hello, I know Hastelloy C276 does reasonably well in clean H2SO4 but corrodes at a much faster rate when the H2SO4 get contaminated with impurities like ferric ions. Is the tantalum surface produced by Ultramet CPT…
High Purity Acids / Electronics
Dan · · 1 reply
Hi, I am involved with a variety of ultra high purity acids for electronic etching applications. The most common acids I deal with are sulfuric acid, hydrochloric acid and HF. My problem trying to maintain the purity of…
Acetic Acid / Acid Resistant Instrumentation
Verlizzo · · 3 replies
Hello, We have process that deals with hot concentrated acetic acid. Typically we utilize zirconium metal for our corrosion resistant process equipment but sometimes we struggle in getting a particular piece of…
Diluting Sulfuric Acid
Verlizzo · · 2 replies
Hello, I have some corrosion issues when trying to dilute hot H2SO4 from 99% down to about 90%. As this dilution creates an exothermic condition I am using a plate and frame heat exchanger to remove the heat.…