Translate the given Spanish text to English

X-17433 PCT -1-.
(ver fórmula (I)).

A valve body (26) is received within the seat (20) and comprises a curved surface (28) and a planar surface (30) that extends across the curved surface (28).
Un cuerpo de valvula (26) es recibido dentro del asiento (20) y comprende una superficie curveada (28) y una superficie plana (30) que se extiende a traves de la superficie curveada (28).

The surrounding wall has an exterior and an interior.

La pared circundante tiene un exterior y un interior.