Hello guys,
I am working on converting a bulk storage heavy oil tank into a bitumen bulk storage tank. This is a big vertical API650 tank O.D. 25m x 12.5m height.
Our company uses holding tanks for pumping at usable temperature for the end users with blends and additives and insulates mainly those tanks for exit mass flow rates of upto 100mm3/hr. The bulk storage tanks are fitted with floor heating coils for low product draw and suction heater for pocket heating of bitumen to transfer into service tanks. So, the bulk storage tanks aren't insulated and extract as much as 5m3/hr with pocket heating on a tubular suction heater. The product will be 60-70 bitumen
Having said that, I have confirmed the new design and operating temperature for this conversion to suit the material, foundation and limits on fill height due to the change in density and temperature of the product inline with our operating procedures for using this tank.
The tank has been API653 inspected and all modifications in the past are in line with API653 to designate it as an API650 tank for the product then.
My work requires putting a new design of suction heater, floor coils and a standby suction heater into this tank and making all the modifications on it in-line with API653 requirements. These floor coils and suction heater will be heated with thermal oil.
Before I commence my work, getting tank inspection done again is imminent, last reports have been very satisfactory in the eyes of a CPEng that I am consulting for this job.
My questions are the following and I will be grateful for getting input from your valuable experiences:
1. Bitumen once filled in the tank will coat the inner walls of the tank as we aren't doing bulk heating. This could be a good corrosion protection layer on the inside wall of the tanks. API 653 requires a tank to be inspected externally every 5 years and internally every 10 years(please correct me if I am wrong)to give it an API650 tank certificate. Is there a workaround for Bitumen Bulk storage tanks to not have this inspection done as the internal walls are already coated with bitumen or there is no possibility of avoiding an internal clean up for full tank inspection? I want to maintain it to API 653.
2. Is it a common practice to do pocket heating rather than insulation and bulk heating for bitumen bulk storage tanks? It all adds up in cost for us and hence we don't unfortunately have the luxury of insulation and cladding. Hence the holding tank on-site with those arrangements.
3. Any guides on API650 certification for Bitumen vertical tanks will be helpful
4. If foundation, fill height, material allowable and design temperature requirements are met for such a conversion, can you please recommend any other parameters to definitely check before making decisions going forward, will be getting in an API650 inspector later.
5. Before I use this tank for any modification on the inside and the outside, as this tank was used eventually for storage of diesel in the past few years, what should be the best practice to follow for clean up of the tank for working inside the tank? Tank trims will need working inside the tank.
My apologies for silly questions , if any, I am limited by resources and quite green to the API tanks.
I am working on converting a bulk storage heavy oil tank into a bitumen bulk storage tank. This is a big vertical API650 tank O.D. 25m x 12.5m height.
Our company uses holding tanks for pumping at usable temperature for the end users with blends and additives and insulates mainly those tanks for exit mass flow rates of upto 100mm3/hr. The bulk storage tanks are fitted with floor heating coils for low product draw and suction heater for pocket heating of bitumen to transfer into service tanks. So, the bulk storage tanks aren't insulated and extract as much as 5m3/hr with pocket heating on a tubular suction heater. The product will be 60-70 bitumen
Having said that, I have confirmed the new design and operating temperature for this conversion to suit the material, foundation and limits on fill height due to the change in density and temperature of the product inline with our operating procedures for using this tank.
The tank has been API653 inspected and all modifications in the past are in line with API653 to designate it as an API650 tank for the product then.
My work requires putting a new design of suction heater, floor coils and a standby suction heater into this tank and making all the modifications on it in-line with API653 requirements. These floor coils and suction heater will be heated with thermal oil.
Before I commence my work, getting tank inspection done again is imminent, last reports have been very satisfactory in the eyes of a CPEng that I am consulting for this job.
My questions are the following and I will be grateful for getting input from your valuable experiences:
1. Bitumen once filled in the tank will coat the inner walls of the tank as we aren't doing bulk heating. This could be a good corrosion protection layer on the inside wall of the tanks. API 653 requires a tank to be inspected externally every 5 years and internally every 10 years(please correct me if I am wrong)to give it an API650 tank certificate. Is there a workaround for Bitumen Bulk storage tanks to not have this inspection done as the internal walls are already coated with bitumen or there is no possibility of avoiding an internal clean up for full tank inspection? I want to maintain it to API 653.
2. Is it a common practice to do pocket heating rather than insulation and bulk heating for bitumen bulk storage tanks? It all adds up in cost for us and hence we don't unfortunately have the luxury of insulation and cladding. Hence the holding tank on-site with those arrangements.
3. Any guides on API650 certification for Bitumen vertical tanks will be helpful
4. If foundation, fill height, material allowable and design temperature requirements are met for such a conversion, can you please recommend any other parameters to definitely check before making decisions going forward, will be getting in an API650 inspector later.
5. Before I use this tank for any modification on the inside and the outside, as this tank was used eventually for storage of diesel in the past few years, what should be the best practice to follow for clean up of the tank for working inside the tank? Tank trims will need working inside the tank.
My apologies for silly questions , if any, I am limited by resources and quite green to the API tanks.
