Valve device in a unit for conducting a product, unit of this type and method for operating the same

A method for operating a unit for conducting a product, said unit comprising

• at least two conduits which are connected to one another via a valve device, said valve device comprising
• a first double seat valve having a first shut-off member and a second shut-off member, and a first leakage space between said first and said second shut-off members,
• a first connection for one of said two conduits on a side of said first shut-off member facing away from said first leakage space,
• a second double seat valve having a third shut-off member and a fourth shut-off member, and a second leakage space between said third and fourth shut-off members,
• a second connection for the other of said two conduits on the side of said fourth shut-off member facing away from said second leakage space,
• said first double seat valve having a first longitudinal axis and said second double seat valve ham a second longitudinal axis, said first double seat valve and said second double seat valve being arranged with the first and second longitudinal axes being in alignment with respect to one another, and
• an intermediate third leakage space arranged between said second shut-off member and said third shut-off member, which is sealed off from said first and second leakage spaces in the closed state of the second and third shut-off member,
• the method comprising:
• opening said first, second, third and fourth shut-off members to transfer a product from the one of said two conduits through the first, second and third leakage spaces into the other of said two conduits.

A valve device for connecting two conduits in a unit for conducting a product, comprising:

• a first double seat valve having a first shut-off member and a second shut-off member, and a first leakage space between said first and said second shut-off members,
• a first connection for one of said two conduits on a side of said first shut-off member facing away from said first leakage space,
• a second double seat valve having a third shut-off member and a fourth shut-off member, and a second leakage space between said third and fourth shut-off members,
• a second connection for the other of said two conduits on the side of said fourth shut-off member facing away from said second leakage space,
• said first double seat valve having a first longitudinal axis and said second double seat valve having a second longitudinal axis, said first double seat valve and said second double seat valve being arranged with the first and second longitudinal axes being in alignment with respect to one another, and
• an intermediate third leakage space arranged between said second shut-off member and said third shut-off member, which is sealed off from said first and second leakage spaces in the closed state of the second and third shut-off member.