PHP - Insertar múltiples filas a través de formulario - PDO PHP MySQL

<?php

.........

// insertar datos

    if ($valid) {

        $pdo = Database::connect();

        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

        $sql = "INSERT INTO valor (tag_idtag, Fecha, Valor) values(?, ?, ?)";

        $q = $pdo->prepare($sql);

        $q->execute(array($tag_idtag,$Fecha,$Valor));

        Database::disconnect();

        header("Location: index.php");

    }

..........

?>

$sql = "INSERT INTO valor (tag_idtag, Fecha, Valor) values(?, ?, ?), (?, ?, ?)";

<form class="form-inline" action="create.php" method="post">

	<div class="form-group <?php echo !empty($tag_idtagError)?'error':'';?>">

	<label class="control-label">Nombre Tag:</label>

		<!--<input name="tag_idtag" type="number"  placeholder="1" value="<?php echo !empty($tag_idtag)?$tag_idtag:'';?>">-->

		<select class="form-control" name="tag_idtag">

		<option value="">Seleccione Tag</option>

		<option value="<?php echo !empty($tag_idtag)?$tag_idtag:'1';?>">Flujometro Entrada PG</option>

		<option value="<?php echo !empty($tag_idtag)?$tag_idtag:'2';?>">Entrada Recolectora PG</option>

		</select>

		<?php if (!empty($tag_idtagError)): ?>

			<span class="help-inline"><?php echo $tag_idtagError;?></span>

		<?php endif; ?>

	</div>

	<div class="form-group <?php echo !empty($FechaError)?'error':'';?>">

	&nbsp;&nbsp;&nbsp;<label class="control-label">Fecha:</label>

		<input class="form-control" name="Fecha" type="date" required placeholder="aa-mm-dd" value="<?php echo !empty($Fecha)?$Fecha:'';?>">

		<?php if (!empty($FechaError)): ?>

			<span class="help-inline"><?php echo $FechaError;?></span>

		<?php endif;?>

	</div>

	<div class="form-group <?php echo !empty($ValorError)?'error':'';?>">

	&nbsp;&nbsp;&nbsp;<label class="control-label">Valor:</label>

		<input class="form-control" name="Valor" type="text" placeholder="123456.7"

		min="0" pattern="\d{7}(\,\d{1})?" title="Positivo de 7 dígitos (,) 1 dígito" value="<?php echo !empty($Valor)?$Valor:'';?>">

		<?php if (!empty($ValorError)): ?>

			<span class="help-inline"><?php echo $ValorError;?></span>

		<?php endif;?>

	</div>

	<p></p>

	<div class="form-actions">

		<div class="col-xs-offset-3 col-xs-4">

		<button type="submit" class="btn btn-success">Crear</button>

		</div>

		<a class="btn btn-default" href="index.php">Cancelar</a>

	</div>

</form>