The Steamboating Forum

A website that describes this material with much detail: http://www.atimetals.com/Documents/ati_316ti_tds_en.pdf

The significant difference I see with respect to the chloride issue is that ordinary stainless steels (304) need to operate with less than 100 PPM (Parts Per Million) chlorides, vs. the 316Ti (your boiler material) which can go up to 2000 PPM, twenty times as much. With sufficient blowdown you can minimize the corrosion issues here. I would recommend you buy a simple TDS (Total Disolved Solids) meter, they cost about $35 USD here, to monitor your boiler water. Lake water and potable water around PA ranges up to a few hunderd PPM, and I try to keep my boiler below about 1500 PPM.

While still not permitted for ASME Code boilers, it is clearly much more appropriate for boiler service than ordinary 304 stainless.

Hi, Fred,

Thank you for the link to the material data sheet and for your recommendations. I obviously do not need to be concerned about corrosion damages. I consulted the inspector who carried out the acceptance test. Due to the very low operating time (less than 100 hours yearly) and to the low exposition to chlorides, the boiler could still be used in 100 years. More important than the material issue for this application is the performance of a professional welding job which he supervised during the entire building process.

My plant is a condensing one, and I use potable water as make-up. However, in order to achieve peace of mind, I intend to regularly check the ppm value. A TDS meter (eBay) is already underway.

Albert

Fred, the PDS meter arrived today. For the tap water I use as make-up it shows 120 ppm. Now I am curious to see how the value for the boiler water develops with the passage of time, and the effect of blowdown.

Thank you again,

Albert