Recipe(tried): How to Can Tomato Juice

I am sorry, but no, what you described is not safe. You need to add bottled lemon juice to tomato products to prevent botulism. That is for both boiling water bath or pressure canning.
Here are the safe guidelines. There is not a safe time for using 15 lb. pressure, not unless you live at high elevations and must use 15 lb. due to the elevation. Tomato juice is always done hot packed, as well. It is part of the safety to can it, so it is not done as a raw packed food. (There is raw pack or hot pack.)

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TOMATO JUICE

QUANTITY: An average of 23 pounds is needed per
canner load of 7 quarts, or an average of 14 pounds per
canner load of 9 pints. A bushel weighs 53 pounds and
yields 15 to 18 quarts of juice--an average of 3-1/4
pounds per quart.

PROCEDURE: Wash, remove stems, and trim off bruised
or discolored portions. To prevent juice from separating,
quickly cut about 1 pound of fruit into quarters and put
directly into saucepan. Heat immediately to boiling while
crushing. Continue to slowly add and crush freshly cut
tomato quarters to the boiling mixture. Make sure the
mixture boils constantly and vigorously while you add the
remaining tomatoes. Simmer 5 minutes after adding all
pieces.

IF YOU ARE NOT CONCERNED ABOUT JUICE SEPARATION,
simply slice or quarter tomatoes into a large saucepan.
Crush, heat, and simmer for 5 minutes before juicing.

Press both types of heated juice through a sieve or
food mill to remove skins and seeds. Acidify by adding
two tablespoons of bottled lemon juice or 1/2 teaspoon of
citric acid per quart of tomatoes. For pints, use one
tablespoon bottled lemon juice or 1/4 teaspoon citric
acid. Acid can be added directly to the jars before
filling with product. Add sugar to offset acid taste, if
desired. Four tablespoons of a 5 percent acidity vinegar
per quart may be used instead of lemon juice or citric
acid. However, vinegar may cause undesirable flavor
changes.

Heat juice again to boiling. Add 1 teaspoon of salt
per quart to the jars, if desired. Fill hot jars with hot
tomato juice, leaving 1/2-inch headspace. Adjust lids and
process.

In a boiling water bath, process pints 35 min. quarts 40 min.

In a dial gauge canner use 11 lb. pressure , pints and quarts 15 min.
In a weighted gauge canner 10 lb. pressure pints and quarts 15 min.