\begin{center}
    \begin{tikzpicture}
        \draw[step = 0.5cm, gray, very thin] (-7.25, -3.25) grid (7.25, 0.25);

        \node[tank, /tank= legs] (A) at (-6.0, -1.5) {};
        \node[dished tank, /tank= legs] (A) at (-4.0, -1.5) {};
        \node[anchor = south] at (-5.0, 0.25) {\textbf{legs}};

        \node[tank, /tank= brackets] (A) at (-1.0, -1.5) {};
        \node[dished tank, /tank= brackets] (A) at (1.0, -1.5) {};
        \node[anchor = south] at (0.0, 0.25) {\textbf{brackets}};

        \node[tank, /tank= skirt] (A) at (4.0, -1.5) {};
        \node[dished tank, /tank= skirt] (A) at (6.0, -1.5) {};
        \node[anchor = south] at (5.0, 0.25) {\textbf{skirt}};
    \end{tikzpicture}
    \\[0.25cm]
    \begin{tikzpicture}
        \draw[step = 0.5cm, gray, very thin] (-7.25, -3.25) grid (7.25, 0.25);

        \node[tank, /tank= ring] (A) at (-6.0, -1.5) {};
        \node[dished tank, /tank= ring] (A) at (-4.0, -1.5) {};
        \node[anchor = south] at (-5.0, 0.25) {\textbf{ring}};

        \node[tank, /tank= jacket] (A) at (-1.0, -1.5) {};
        \node[dished tank, /tank= jacket] (A) at (1.0, -1.5) {};
        \node[anchor = south] at (0.0, 0.25) {\textbf{jacket}};

        \node[tank, /tank= electrical heating] (A) at (4.0, -1.5) {};
        \node[dished tank, /tank= electrical heating] (A) at (6.0, -1.5) {};
        \node[anchor = south] at (5.0, 0.25) {\textbf{electrical heating}};
    \end{tikzpicture}
    \\[0.25cm]
    \begin{tikzpicture}
        \draw[step = 0.5cm, gray, very thin] (-7.25, -3.25) grid (7.25, 0.25);

        \node[tank, /tank= insulation] (A) at (-6.0, -1.5) {};
        \node[dished tank, /tank= insulation] (A) at (-4.0, -1.5) {};
        \node[anchor = south] at (-5.0, 0.25) {\textbf{insulation}};

        \node[tank, /tank= surface indication] (A) at (-1.0, -1.5) {};
        \node[dished tank, /tank= surface indication] (A) at (1.0, -1.5) {};
        \node[anchor = south] at (0.0, 0.25) {\textbf{surface indication}};

        \node[tank, /tank= full-tube coil] (B) at (4.0, -1.5) {};
        \node[dished tank, /tank= full-tube coil] (A) at (6.0, -1.5) {};
        \node[anchor = south] at (5.0, 0.25) {\textbf{full-tube coil}};
    \end{tikzpicture}
\end{center}
\begin{center}
    \begin{tikzpicture}
        \draw[step = 0.5cm, gray, very thin] (-7.25, -3.25) grid (7.25, 0.25);

        \node[tank, /tank= semi-tube coil] (B) at (-6.0, -1.5) {};
        \node[dished tank, /tank= semi-tube coil] (A) at (-4.0, -1.5) {};
        \node[anchor = south] at (-5.0, 0.25) {\textbf{semi-tube coil}};

        % \node[tank, /tank= dished jacket] (A) at (-1.0, -1.5) {};
        \node[dished tank, /tank= dished jacket] (A) at (0.0, -1.5) {};
        \node[anchor = south] at (0.0, 0.25) {\textbf{dished jacket}};
    \end{tikzpicture}
\end{center}