Rinse beans. In a large saucepan combine beans and enough water to cover them. Bring to boiling; reduce heat. Simmer for 2 minutes. Remove from heat. Cover and let stand 1 hour. (Or, omit boiling and soak beans overnight.)
Drain and rinse the beans. In a 4- or 6-quart pressure cooker combine the beans, onion, celery, water, and oil.
Lock lid in place. Place pressure regulator on vent pipe (if you have a first-generation cooker). Over high heat, bring cooker up to pressure. Reduce heat just enough to maintain pressure and pressure regulator rocks gently; cook for 8 minutes.
Quick-release the pressure. Carefully remove lid. Drain beans. Return the beans to the pressure cooker.
Stir in the sweet pepper, chili powder, dry mustard, crushed red pepper, salt, undrained tomatoes, and tomato sauce. Bring to boiling. Simmer, uncovered, about 10 minutes or until desired consistency. If desired, serve with sour cream, sliced olives, and cheese. Makes 6 main-dish servings (6 cups).