Metal to metal contact affects to galvanize corrosion, not crevice, but may accelerate crevice. FYI, crevice corrosion usually occurs in gaskets, washers, insulation material, fastener heads, surface deposits, lacked coatings, threads, lap joints and clamps due to changes in local chemistry (different corrosion system between crevice/shielded area and metallic surface). If possible, you may apply inhibitor.

Tanya – Alda Adrina

Dear all,

Our piping experiences crevice corrosion at the bottom of the pipes, and that case happens in the pipe shoe area of the piping. What can we do to solve this problem? For info, the pipe has metal-to-metal contact with the shoe.
By adding a non-metal pad in between pipe and the shoe, will it make a better corrosion prevention? Thanks before.

Tanggapan 1 – Isya Muhajirin

Alda,

You’re so correct, by adding non-metal pad in between would decrease or even prevent corrosion to occur. Additional coating on each pad and shoe surface make it even better.
Good luck.

Tanggapan 2 – Dwi A.S. Utomo

Just a thought,

The non metal pad should be made from a compressible material such as rubber sheet or other soft elastomers/polymers. Otherwise the ‘crevice’ will still be present and the corrosion continues.
Coating (a good application at that) will surely cut-off the corrosion significantly.

Tanggapan 3 – Sigit kumoro bekti

Dear Alda,

I’m not a corrosion guy, in my opinion, may be your case refers to galvanic corrosion which can be generated belows:

Galvanic corrosion: two connected metals + single environment

As your case, there are two connected metal with single environment (i guess), if this happend to your case, laminated with non-metal can be a good solution. and it prevent to corrosion problem.

But if crevice corrosion happend, perhaps you shoul determine what environments that effect to metal and sometimes like pitting corrosion. the crevice corrosion can be generated as belows:

one metal part + two connected environments

but sometimes galvanic effect also play a role in crevice. i hope this help you.

Tanggapan 4 – Farizan Riadhi

Alda, but makes sure no fluid can penetrate the crevice under the pad. Metal to metal contact affects to galvanize corrosion, not crevice, but may accelerate crevice. FYI, crevice corrosion usually occurs in gaskets, washers, insulation material, fastener heads, surface deposits, lacked coatings, threads, lap joints and clamps due to changes in local chemistry (different corrosion system between crevice/shielded area and metallic surface). If possible, you may apply inhibitor. That’s my opinion, but please consider to consult with your expert. I’m newbie =P

Tanggapan 5 – Dwi A.S. Utomo

Dear Alda,

Reading some of the replies, I got a little cirious.

Please tell:

Is this case an external or internal corrosion? My bet is external corrosion, but I might be wrong. If this is external corrosion, then I think applying corrosion inhibitor is somewhat useless.
Was the pipe shoe made of different material (SS?) from the pipe (CS?)? If the shoe and the pipe was not made of different material, then I think galvanic corrosion is out of question. But if different metal is really the case, then I suggest beside inserting a non-metal pad, you also paint the contact surface of the more noble metal (the shoe).

Tanggapan 6 – muhammad rifai

Ini mungkin bisa membantu penjelasan dan pemecahannya, pakai bahasa inggris jadi mungkin tinggal copy dan boss percaya (bukankah kebanyakan masih seperti ini?).. he he he… silahkan buka site dibawah. di dalamnya juga ada link pabrikan yang membuat supportnya..

www.cathodicprotectionpapers.com/6pipesupports

Intinya… bagaimana caranya agar bagian-bagian sempit itu dihindari dimana di bagian sempit itu uap air yang menjadi air bisa terjebak… dengan bentuk dan bahan support yang diuraikan di tulisan itu, air yang terjebak bisa diminimalkan.

Tapi menurut saya, selain dengan cara tersebut… bisa dicoba dengan pengecatan pakai cat yang memang didesain tahan terhadap air, selain pemakaian semacam grease dipermukaan yang rentan terjebaknya uap air.